FormalGeo 2.2.1

Formal representation and solving for Euclidean plane geometry problems.

FormalGeo

FormalGeo is a framework for formal representation and solving of plane geometry, encompassing the entire workflow including theory, formal systems, reasoning-computation engines, datasets, evaluation metrics, and neural-symbolic solvers. FormalGeo is currently maintained by the FormalGeo Development Team, an open-source research organization dedicated to advancing the frontiers of artificial intelligence through formal mathematical reasoning. We primarily focus on automatically Geometry Problem-Solving at or beyond the difficulty of the International Mathematical Olympiad (IMO) to explore the boundaries of machine abstraction and reasoning.

Plane geometry, characterized by its multimodal knowledge representation, rigorous axiomatic structure, and reliance on spatial intuition, serves as a natural benchmark for evaluating an AI system’s capabilities in perception, comprehension, and logical deduction. We aim to empower machines with mathematical reasoning abilities that match or surpass those of humans, thereby establishing a new paradigm for General Artificial Intelligence that integrates Symbolism, Connectionism, and Behaviorism. Our goal is to construct a verifiable, interpretable, and scalable system for automated Geometric Knowledge Discovery (GKD) and Geometric Problem-Solving (GPS), laying the foundation for AI-driven mathematical discovery, formal verification, and intelligent education. More information about FormalGeo will be found in homepage.

Older versions before 2.0.1, which we refer to as alpha version, have been unmaintained since December 2025. If you still wish to access the alpha version code, you can check out the alpha branch. On April 2026, we released beta version, a new solver version that unifies geometric configuration construction, problem-solving, and solution generation. By integrating modern neuro-symbolic architectures, the vision of building a geometric problem-solving system that surpasses human performance is becoming a reality.

The released open-source datasets can be found in the datasets.json file. If you use these datasets, please cite them appropriately according to the citation information provided in the JSON file.

Installation

For users:
We recommend using Conda to manage Python development environments. FormalGeo has been deployed to PyPi, allowing for easy installation via the pip command.

$ conda create -n <your_env_name> python=3.10
$ conda activate <your_env_name>
$ pip install formalgeo

For developers:
This project uses pyproject.toml to store project metadata. The command pip install -e . reads file pyproject.toml, automatically installs project dependencies, and installs the current project in an editable mode into the environment's library. It is convenient for project development and testing.

$ git clone --depth 1 https://github.com/FormalGeo/FormalGeo.git
$ cd FormalGeo
$ conda create -n <your_env_name> python=3.10
$ conda activate <your_env_name>
$ pip install -e .

Example

We hereby present the formal representation and the interactive solving process for IMO 2025 Problem 2. All example code can be found in tests/test.py.The original problem statement is as follows:

Let Ω and Γ be circles with centres M and N, respectively, such that the radius of Ω is less than the radius of Γ. Suppose circles Ω and Γ intersect at two distinct points A and B. Line MN intersects Ω at C and Γ at D, such that points C, M, N and D lie on the line in that order. Let P be the circumcentre of triangle ACD. Line AP intersects Ω again at E ≠ A. Line AP intersects Γ again at F ≠ A. Let H be the orthocentre of triangle PMN.

Prove that the line through H parallel to AP is tangent to the circumcircle of triangle BEF.

(The orthocentre of a triangle is the point of intersection of its altitudes.)

First, start Python and import the necessary classes and methods:

>>> from formalgeo import GeometricConfiguration, load_json, parse_gdl, debug_execute

First, we need to configure the geometry formal system using Geometry Definition Language (GDL). We provide an example of a formal system in tests/gdl.json. After that, we parse the GDL and initialize a geometry configuration instance:

>>> parsed_gdl = parse_gdl(load_json('gdl.json'))
>>> gc = GeometricConfiguration(parsed_gdl=parsed_gdl)

Subsequently, we can use the Geometric Construction Language (GCL) to construct the geometric figure step by step. The description of the geometric problem can be translated into the following GCL:

>>> debug_execute(gc.construct, ['Circle(Γ)&Circle(Ω):IntersectBetweenCircle(Ω,Γ)&G(Sub(Γ.rc,Ω.rc))', 19])
>>> debug_execute(gc.construct, ['Point(M):CenterOfCircle(M,Ω)'])
>>> debug_execute(gc.construct, ['Point(N):CenterOfCircle(N,Γ)'])
>>> debug_execute(gc.construct, ['Point(A):PointOnCircle(A,Ω)&PointOnCircle(A,Γ)&PointLeftSegment(A,N,M)'])
>>> debug_execute(gc.construct, ['Point(B):PointOnCircle(B,Ω)&PointOnCircle(B,Γ)&PointLeftSegment(B,M,N)'])
>>> debug_execute(gc.construct, ['Line(a):PointOnLine(M,a)&PointOnLine(N,a)'])
>>> debug_execute(gc.construct, ['Point(C):PointOnLine(C,a)&PointOnCircle(C,Ω)&PointLeftSegment(C,A,B)'])
>>> debug_execute(gc.construct, ['Point(D):PointOnLine(D,a)&PointOnCircle(D,Γ)&PointLeftSegment(D,B,A)'])
>>> debug_execute(gc.construct, ['Line(c):PointOnLine(A,c)&PointOnLine(D,c)'])
>>> debug_execute(gc.construct, ['Line(d):PointOnLine(A,d)&PointOnLine(C,d)'])
>>> debug_execute(gc.construct, ['Point(P):CircumcenterOfTriangle(P,C,d,A,c,D,a)'])
>>> debug_execute(gc.construct, ['Line(p):PointOnLine(A,p)&PointOnLine(P,p)'])
>>> debug_execute(gc.construct, ['Point(E):PointOnLine(E,p)&PointOnCircle(E,Ω)&~SamePoint(E,A)'])
>>> debug_execute(gc.construct, ['Point(F):PointOnLine(F,p)&PointOnCircle(F,Γ)&~SamePoint(F,A)'])
>>> debug_execute(gc.construct, ['Line(n):PointOnLine(P,n)&PointOnLine(M,n)'])
>>> debug_execute(gc.construct, ['Line(m):PointOnLine(P,m)&PointOnLine(N,m)'])
>>> debug_execute(gc.construct, ['Point(H):OrthocenterOfTriangle(H,P,n,M,a,N,m)'])
>>> debug_execute(gc.construct, ['Line(f):PointOnLine(B,f)&PointOnLine(E,f)'])
>>> debug_execute(gc.construct, ['Line(e):PointOnLine(B,e)&PointOnLine(F,e)'])
>>> debug_execute(gc.construct, ['Circle(Φ):CircumcircleOfTriangle(Φ,B,f,E,p,F,e)'])

When calling the functions of gc, we use debug_execute(func, args) to obtain debugging information. Alternatively, we can directly execute the functions of gc, such as gc.construct('Point(M): CenterOfCircle(M,Ω)'). The original geometry problem description uses 20 GCLs. To solve the current problem, an additional 22 auxiliary GCLs are required:

>>> debug_execute(gc.construct, ['Line(x):PointOnLine(M,x)&PointOnLine(E,x)'])
>>> debug_execute(gc.construct, ['Line(y):PointOnLine(N,y)&PointOnLine(F,y)'])
>>> debug_execute(gc.construct, ['Point(T):PointOnLine(T,x)&PointOnLine(T,y)'])
>>> debug_execute(gc.construct, ['Line(t):PointOnLine(H,t)&PointOnLine(T,t)'])
>>> debug_execute(gc.construct, ['Circle(Δ):CircumcircleOfTriangle(Δ,C,d,A,c,D,a)'])
>>> debug_execute(gc.construct, ['Line(g):PointOnLine(P,g)&PointOnLine(C,g)'])
>>> debug_execute(gc.construct, ['Line(h):PointOnLine(P,h)&PointOnLine(D,h)'])
>>> debug_execute(gc.construct, ['Line(i):PointOnLine(M,i)&PointOnLine(H,i)'])
>>> debug_execute(gc.construct, ['Line(j):PointOnLine(N,j)&PointOnLine(H,j)'])
>>> debug_execute(gc.construct, ['Line(k):PointOnLine(A,k)&PointOnLine(M,k)'])
>>> debug_execute(gc.construct, ['Line(l):PointOnLine(A,l)&PointOnLine(N,l)'])
>>> debug_execute(gc.construct, ['Line(u):PointOnLine(B,u)&PointOnLine(C,u)'])
>>> debug_execute(gc.construct, ['Line(v):PointOnLine(A,v)&PointOnLine(B,v)'])
>>> debug_execute(gc.construct, ['Line(w):PointOnLine(B,w)&PointOnLine(D,w)'])
>>> debug_execute(gc.construct, ['Point(X):PointOnLine(X,n)&PointOnLine(X,d)'])
>>> debug_execute(gc.construct, ['Point(Y):PointOnLine(Y,m)&PointOnLine(Y,c)'])
>>> debug_execute(gc.construct, ['Point(G):CenterOfCircle(G,Φ)'])
>>> debug_execute(gc.construct, ['Line(b):PointOnLine(T,b)&PointOnLine(G,b)'])
>>> debug_execute(gc.construct, ['Point(Q):PointOnLine(Q,p)&PointOnLine(Q,b)'])
>>> debug_execute(gc.construct, ['Line(q):PointOnLine(F,q)&PointOnLine(G,q)'])
>>> debug_execute(gc.construct, ['Line(o):PointOnLine(E,o)&PointOnLine(G,o)'])
>>> debug_execute(gc.construct, ['Point(K):PointOnLine(K,v)&PointOnLine(K,a)'])

At this point, the construction of the geometry problem is complete, and we can proceed to plot the geometric figure:

>>> gc.draw_sg(save_path='../outputs/', file_format='png')

You will obtain an image like this:

Then, set the problem goal:

>>> debug_execute(gc.set_goal, ['ParallelBetweenLine(p,t)&TangentBetweenLineAndCircle(t,Φ)'])

After the construction is complete and goal is set, we can apply theorems. These theorems are pre-defined in the GDL, and the solver will perform rigorous reasoning and calculations based on their definitions to derive new facts:

>>> # common sense
>>> debug_execute(gc.apply, ['circumcenter_of_triangle_property_center_of_circle(P,Δ,C,d,A,c,D,a)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_multiple_forms(Δ,C,d,A,c,D,a)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_multiple_forms(Δ,A,c,D,a,C,d)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_point_on_circle(Δ,A,c,D,a,C,d)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_point_on_circle(Δ,D,a,C,d,A,c)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_point_on_circle(Δ,C,d,A,c,D,a)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Δ,P,C)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Δ,P,A)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Δ,P,D)'])
>>> 
>>> # prove ∠gd = ∠dp
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(P,C,P,A)'])
>>> debug_execute(gc.apply, ['triangle_determination(P,g,C,d,A,p)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(P,g,C,d,A,p)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(P,g,C,d,A,p)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(g,d,d,p)'])
>>> 
>>> # prove ∠pc = ∠ch
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(P,A,P,D)'])
>>> debug_execute(gc.apply, ['triangle_determination(P,p,A,c,D,h)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(P,p,A,c,D,h)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(P,p,A,c,D,h)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(p,c,c,h)'])
>>> 
>>> # prove ∠ga = ∠ah
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(P,C,P,D)'])
>>> debug_execute(gc.apply, ['triangle_determination(P,g,C,a,D,h)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(P,g,C,a,D,h)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(P,g,C,a,D,h)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(g,a,a,h)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Ω,M,C)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Ω,M,A)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Ω,M,E)'])
>>> 
>>> # prove ∠ad = ∠dk
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(M,C,M,A)'])
>>> debug_execute(gc.apply, ['triangle_determination(M,a,C,d,A,k)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(M,a,C,d,A,k)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(M,a,C,d,A,k)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(a,d,d,k)'])
>>> 
>>> # prove ∠kp = ∠px
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(M,A,M,E)'])
>>> debug_execute(gc.apply, ['triangle_determination(M,k,A,p,E,x)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(M,k,A,p,E,x)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(M,k,A,p,E,x)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(k,p,p,x)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Γ,N,A)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Γ,N,D)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Γ,N,F)'])
>>> 
>>> # prove ∠lc = ∠ca
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(N,A,N,D)'])
>>> debug_execute(gc.apply, ['triangle_determination(N,l,A,c,D,a)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(N,l,A,c,D,a)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(N,l,A,c,D,a)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(l,c,c,a)'])
>>> 
>>> # prove ∠yp = ∠pl
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(N,F,N,A)'])
>>> debug_execute(gc.apply, ['triangle_determination(N,y,F,p,A,l)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(N,y,F,p,A,l)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(N,y,F,p,A,l)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(y,p,p,l)'])
>>> debug_execute(gc.apply, ['line_property_angle_addition(C,g,a,d)'])
>>> debug_execute(gc.apply, ['line_property_angle_addition(A,d,k,p)'])
>>> debug_execute(gc.apply, ['line_property_angle_addition(A,p,l,c)'])
>>> debug_execute(gc.apply, ['line_property_angle_addition(D,c,a,h)'])
>>> 
>>> # prove y // k
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(y,p,k,p)'])
>>> debug_execute(gc.apply, ['parallel_determination_angle_equal(y,k,p)'])
>>> 
>>> # prove x // l
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(p,x)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(p,l)'])
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(x,p,l,p)'])
>>> debug_execute(gc.apply, ['parallel_determination_angle_equal(x,l,p)'])
>>> debug_execute(gc.apply, ['perpendicular_bisector_determination_center_line_and_common_chord(Ω,Γ,M,N,a,A,B,v)'])
>>> debug_execute(gc.apply, ['perpendicular_bisector_property_perpendicular_between_line(a,v,A,B)'])
>>> 
>>> # prove ∠fp = 2∠ad
>>> debug_execute(gc.apply, ['perpendicular_between_line_property_multiple_forms(a,v)'])
>>> debug_execute(gc.apply, ['perpendicular_between_line_property_angle(a,v)'])
>>> debug_execute(gc.apply, ['perpendicular_between_line_property_angle(v,a)'])
>>> debug_execute(gc.apply, ['perpendicular_bisector_property_distance_equal(a,v,A,B,C)'])
>>> debug_execute(gc.apply, ['triangle_determination(C,d,A,v,B,u)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(C,d,A,v,B,u)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(C,d,A,v,B,u)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(d,v,v,u)'])
>>> debug_execute(gc.apply, ['triangle_determination(A,v,K,a,C,d)'])
>>> debug_execute(gc.apply, ['triangle_determination(B,u,C,a,K,v)'])
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(A,v,K,a,C,d)'])
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(B,u,C,a,K,v)'])
>>> debug_execute(gc.apply, ['line_property_angle_addition(C,u,a,d)'])
>>> debug_execute(gc.apply, ['concyclic_between_points_determination_same_circle(Ω,B,C,A,E)'])
>>> debug_execute(gc.apply, ['concyclic_between_points_property_inscribed_angle_sum(B,u,C,d,A,p,E,f)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(p,f)'])
>>> 
>>> # prove ∠pe = 2∠ca
>>> debug_execute(gc.apply, ['perpendicular_bisector_property_multiple_forms(a,v,A,B)'])
>>> debug_execute(gc.apply, ['perpendicular_bisector_property_distance_equal(a,v,B,A,D)'])
>>> debug_execute(gc.apply, ['triangle_determination(D,w,B,v,A,c)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(D,w,B,v,A,c)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(D,w,B,v,A,c)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(w,v,v,c)'])
>>> debug_execute(gc.apply, ['triangle_determination(D,w,B,v,K,a)'])
>>> debug_execute(gc.apply, ['triangle_determination(D,a,K,v,A,c)'])
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(D,w,B,v,K,a)'])
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(D,a,K,v,A,c)'])
>>> debug_execute(gc.apply, ['line_property_angle_addition(D,c,a,w)'])
>>> debug_execute(gc.apply, ['concyclic_between_points_determination_same_circle(Γ,B,A,D,F)'])
>>> debug_execute(gc.apply, ['concyclic_between_points_property_inscribed_angle_equal(B,w,A,c,D,e,F,p)'])
>>> 
>>> # prove ∠ay = 2∠ad
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(M,a,C,d,A,k)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(a,k)'])
>>> debug_execute(gc.apply, ['parallel_property_angle_equal(y,k,a)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(y,a,k,a)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(a,y)'])
>>> 
>>> # prove ∠la = 2∠ca
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(N,l,A,c,D,a)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(a,l)'])
>>> 
>>> # prove ∠xy = 2∠ad + 2∠ca
>>> debug_execute(gc.apply, ['line_property_angle_addition(N,l,a,y)'])
>>> debug_execute(gc.apply, ['parallel_property_multiple_forms(x,l)'])
>>> debug_execute(gc.apply, ['parallel_property_angle_equal(l,x,y)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(l,y,x,y)'])
>>> 
>>> # prove ∠ef + ∠xy = 180° (T on Φ)
>>> debug_execute(gc.apply, ['triangle_determination(F,e,B,f,E,p)'])
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(F,e,B,f,E,p)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_multiple_forms(Φ,B,f,E,p,F,e)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_multiple_forms(Φ,E,p,F,e,B,f)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_point_on_circle(Φ,B,f,E,p,F,e)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_point_on_circle(Φ,E,p,F,e,B,f)'])
>>> debug_execute(gc.apply, ['circumcircle_of_triangle_property_point_on_circle(Φ,F,e,B,f,E,p)'])
>>> debug_execute(gc.apply, ['concyclic_between_points_determination_inscribed_angle_sum(F,e,B,f,E,x,T,y)'])
>>> debug_execute(gc.apply, ['point_on_circle_determination_concyclic(Φ,F,B,E,T)'])
>>> 
>>> # prove m ⊥ c
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(N,P,N,P)'])
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(A,N,D,N)'])
>>> debug_execute(gc.apply, ['triangle_determination(A,l,N,m,P,p)'])
>>> debug_execute(gc.apply, ['triangle_determination(D,h,P,m,N,a)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_determination_sss(A,l,N,m,P,p,D,a,N,m,P,h)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_property_angle_equal(A,l,N,m,P,p,D,a,N,m,P,h)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(l,m,m,a)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(l,m)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(m,a)'])
>>> debug_execute(gc.apply, ['triangle_determination(Y,m,N,l,A,c)'])
>>> debug_execute(gc.apply, ['triangle_determination(Y,c,D,a,N,m)'])
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(m,l,a,m)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_determination_asa(Y,m,N,l,A,c,Y,m,N,a,D,c)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_property_multiple_forms(Y,m,N,l,A,c,Y,m,N,a,D,c)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_property_multiple_forms(N,l,A,c,Y,m,N,a,D,c,Y,m)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_property_angle_equal(A,c,Y,m,N,l,D,c,Y,m,N,a)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(c,m,m,c)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(m,c)'])
>>> 
>>> # prove n ⊥ d
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(C,M,A,M)'])
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(M,P,M,P)'])
>>> debug_execute(gc.apply, ['triangle_determination(C,a,M,n,P,g)'])
>>> debug_execute(gc.apply, ['triangle_determination(A,p,P,n,M,k)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_determination_sss(C,a,M,n,P,g,A,k,M,n,P,p)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_property_angle_equal(C,a,M,n,P,g,A,k,M,n,P,p)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(a,n,n,k)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(a,n)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(n,k)'])
>>> debug_execute(gc.apply, ['triangle_determination(X,n,M,a,C,d)'])
>>> debug_execute(gc.apply, ['triangle_determination(X,d,A,k,M,n)'])
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(n,a,k,n)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_determination_asa(X,n,M,a,C,d,X,n,M,k,A,d)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_property_multiple_forms(X,n,M,a,C,d,X,n,M,k,A,d)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_property_multiple_forms(M,a,C,d,X,n,M,k,A,d,X,n)'])
>>> debug_execute(gc.apply, ['mirror_congruent_triangle_property_angle_equal(C,d,X,n,M,a,A,d,X,n,M,k)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(d,n,n,d)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(n,d)'])
>>> 
>>> # prove i // c
>>> debug_execute(gc.apply, ['orthocenter_of_triangle_property_multiple_forms(H,P,n,M,a,N,m)'])
>>> debug_execute(gc.apply, ['orthocenter_of_triangle_property_perpendicular(H,i,M,a,N,m,P,n)'])
>>> debug_execute(gc.apply, ['perpendicular_between_line_property_angle(i,m)'])
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(i,m,c,m)'])
>>> debug_execute(gc.apply, ['parallel_determination_angle_equal(i,c,m)'])
>>> 
>>> # prove ∠xi = ∠ia
>>> debug_execute(gc.apply, ['parallel_property_angle_equal(i,c,a)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(i,a,c,a)'])
>>> debug_execute(gc.apply, ['line_property_angle_addition(M,x,i,a)'])
>>> debug_execute(gc.apply, ['parallel_property_angle_equal(x,l,a)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(x,a,l,a)'])
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(x,i,i,a)'])
>>> debug_execute(gc.apply, ['angle_bisector_determination_angle_equal(M,i,x,a)'])
>>> 
>>> # prove j // d
>>> debug_execute(gc.apply, ['orthocenter_of_triangle_property_multiple_forms(H,M,a,N,m,P,n)'])
>>> debug_execute(gc.apply, ['orthocenter_of_triangle_property_perpendicular(H,j,N,m,P,n,M,a)'])
>>> debug_execute(gc.apply, ['perpendicular_between_line_property_angle(j,n)'])
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(d,n,j,n)'])
>>> debug_execute(gc.apply, ['parallel_determination_angle_equal(d,j,n)'])
>>> 
>>> # prove ∠aj = ∠jy
>>> debug_execute(gc.apply, ['parallel_property_angle_equal(d,j,a)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(d,a,j,a)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(a,d)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(a,j)'])
>>> debug_execute(gc.apply, ['line_property_angle_addition(N,a,j,y)'])
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(a,j,j,y)'])
>>> debug_execute(gc.apply, ['angle_bisector_determination_angle_equal(N,j,a,y)'])
>>> 
>>> # prove ∠yt = ∠tx
>>> debug_execute(gc.apply, ['triangle_determination(T,x,M,a,N,y)'])
>>> debug_execute(gc.apply, ['incenter_of_triangle_determination_angle_bisector(H,i,j,T,x,M,a,N,y)'])
>>> debug_execute(gc.apply, ['incenter_of_triangle_property_angle_bisector(H,t,T,x,M,a,N,y)'])
>>> debug_execute(gc.apply, ['angle_bisector_property_equal_angle(T,t,y,x)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(y,t,t,x)'])
>>> 
>>> # prove t // p
>>> debug_execute(gc.apply, ['line_property_angle_addition(T,y,t,x)'])
>>> debug_execute(gc.apply, ['triangle_determination(F,p,E,x,T,y)'])
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(F,p,E,x,T,y)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(y,x)'])
>>> debug_execute(gc.apply, ['equal_angle_determination_algebraic(t,x,p,x)'])
>>> debug_execute(gc.apply, ['parallel_determination_angle_equal(t,p,x)'])
>>> debug_execute(gc.apply, ['parallel_property_multiple_forms(t,p)'])
>>> 
>>> # prove b ⊥ p
>>> debug_execute(gc.apply, ['triangle_determination(G,q,F,p,Q,b)'])
>>> debug_execute(gc.apply, ['triangle_determination(G,b,Q,p,E,o)'])
>>> debug_execute(gc.apply, ['triangle_determination(G,q,F,p,E,o)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Φ,G,F)'])
>>> debug_execute(gc.apply, ['circle_property_radius_equal(Φ,G,E)'])
>>> debug_execute(gc.apply, ['equal_distance_point_to_point_determination_algebraic(G,F,G,E)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_determination_distance_equal(G,q,F,p,E,o)'])
>>> debug_execute(gc.apply, ['isosceles_triangle_property_angle_equal(G,q,F,p,E,o)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(q,p,p,o)'])
>>> debug_execute(gc.apply, ['arc_property_central_angle_and_inscribed_angle(Φ,G,T,F,E,b,q,x,p)'])
>>> debug_execute(gc.apply, ['arc_property_central_angle_and_inscribed_angle(Φ,G,E,T,F,o,b,p,y)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(b,o)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(q,b)'])
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(G,q,F,p,Q,b)'])
>>> debug_execute(gc.apply, ['triangle_property_angle_sum(G,b,Q,p,E,o)'])
>>> debug_execute(gc.apply, ['line_property_adjacent_complementary_angle(p,b)'])
>>> debug_execute(gc.apply, ['parallel_property_angle_equal(t,p,b)'])
>>> debug_execute(gc.apply, ['equal_angle_property_algebraic(t,b,p,b)'])
>>> 
>>> # prove t ⊥ p
>>> debug_execute(gc.apply, ['perpendicular_between_line_determination_angle(t,b)'])
>>> debug_execute(gc.apply, ['perpendicular_between_line_property_multiple_forms(t,b)'])
>>> debug_execute(gc.apply, ['tangent_between_line_and_circle_determination_perpendicular(Φ,G,b,T,t)'])

Additionally, at any stage of the construction or reasoning process, we can inspect the current state of the problem. The show_gc function can be used to print detailed information about the current problem, including constructions, facts, goals, etc.:

>>> gc.show_gc()

You will see output similar to the following:

Constructions:
0  Circle(Γ)&Circle(Ω):IntersectBetweenCircle(Ω,Γ)&G(Sub(Γ.rc,Ω.rc))
   branch: 1
   target_entities: ['Circle(Γ)', 'Circle(Ω)']
   dependent_entities: []
   added_facts: ['IntersectBetweenCircle(Ω,Γ)', 'G(Γ.rc-Ω.rc)']
   equations: 
   inequalities: G((Γ.r+Ω.r)**2-(Γ.u-Ω.u)**2-(Γ.v-Ω.v)**2), G(Γ.r-Ω.r), L((-Γ.r+Ω.r)**2-(Γ.u-Ω.u)**2-(Γ.v-Ω.v)**2)
   solved_value: [(Γ.u, Γ.v, Γ.r, Ω.u, Ω.v, Ω.r), (0.6838, 0.0491, 1.1491, -0.2555, 1.1924, 0.868)]

...

Entity - Point:
fact_id     instance       values                         premise_ids              entity_ids               operation_id   operation                                                                                           
4           (M)            (-0.2555, 1.1924)              {1}                      {1}                      1              Construct: Point(M):CenterOfCircle(M,Ω)                                                             
6           (N)            (0.6838, 0.0491)               {0}                      {0}                      2              Construct: Point(N):CenterOfCircle(N,Γ)                                                             
8           (A)            (-0.4275, 0.3415)              {0,1,4,6}                {0,1,4,6}                3              Construct: Point(A):PointOnCircle(A,Ω)&PointOnCircle(A,Γ)&PointLeftSegment(A,N,M)                   

...

Goals:
goal_id    sub_goal_id_tree                                       root  status    premise_ids               operation_id   operation                                                                                           
0          (0,&,1)                                                None  1         {313,334}                 42             Auto: set_initial_goal                                                                              
1          (2,&,(3,&,(4,&,(5,&,(6,&,7)))))                        1     1         {71,108,110,111,303,...}  43             Decompose: tangent_between_line_and_circle_determination_perpendicular(Φ,G,b,T,t)                   
2          8                                                      7     1         {332}                     44             Decompose: perpendicular_between_line_property_multiple_forms(t,b)                                  

...

Sub Goals:
sub_goal_id predicate                     instance                                goal_id   leaf_goal_ids                 status         premise_ids                                       
0           ParallelBetweenLine           (p,t)                                   0         {6}                           1              {313}                                             
1           TangentBetweenLineAndCircle   (t,Φ)                                   0         {1}                           1              {334}                                             

...

You can also obtain the serialized representation of the current problem. All vocabulary tokens are available in src/formalgeo/tools.py under the letters list. This is specifically prepared for integration with modern deep neural networks and deep learning approaches:

>>> print(gc.get_gc())

You will see output similar to the following:

['<init_fact>', 'Circle', 'Γ', '&', 'Circle', 'Ω', '&', 'IntersectBetweenCircle', 'Ω', 'Γ', '&', 'G', 'Γ', '.', 'r', 'c', '-', 'Ω', '.', 'r', 'c', '<premises>', 'Circle', 'Ω', '<operation>', 'Point', 'M', ':', 'CenterOfCircle', 'M', 'Ω', '<conclusion>', 'Point', 'M', '|', 'CenterOfCircle', 'M', 'Ω', ..., '<premises>', 'Line', 'm', '&', 'Line', 'l', '<operation>', 'line_property_adjacent_complementary_angle', 'l', 'm', '<conclusion>', 'Eq', 'l', 'm', '.', 'm', 'a', '+', 'm', 'l', '.', 'm', 'a', '-', 'nums', ..., '<goal>', 'Triangle', 'G', 'q', 'F', 'p', 'E', 'o', '<sub_goals>', 'PointOnLine', 'G', 'q', '&', 'PointOnLine', 'F', 'q', '&', 'PointOnLine', 'F', 'p', '&', 'PointOnLine', 'E', 'p', '&', 'PointOnLine', 'E', 'o', '&', 'PointOnLine', 'G', 'o']

In addition to forward solving, FormalGeo also supports backward solving. Forward solving starts from known facts, continuously applying theorems to derive new facts until the goal is included in the facts. Backward solving starts from the goal, applying theorems to decompose the goal into sub-goals until all sub-goals in a certain branch are initial facts. The usage of backward solving is similar to forward solving: first, initialize the geometry configuration, then apply 42 GCL statements, set the solving goal, and subsequently execute backward reasoning:

>>> debug_execute(gc.decompose, ['tangent_between_line_and_circle_determination_perpendicular(Φ,G,b,T,t)'])
>>> debug_execute(gc.decompose, ['perpendicular_between_line_property_multiple_forms(t,b)'])
>>> debug_execute(gc.decompose, ['perpendicular_between_line_determination_angle(t,b)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(t,b,p,b)'])
>>> debug_execute(gc.decompose, ['parallel_property_angle_equal(t,p,b)'])
>>> debug_execute(gc.decompose, ['parallel_property_multiple_forms(t,p)'])
>>> debug_execute(gc.decompose, ['parallel_determination_angle_equal(t,p,x)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(t,x,p,x)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(F,p,E,x,T,y)'])
>>> debug_execute(gc.decompose, ['triangle_determination(F,p,E,x,T,y)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(T,y,t,x)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(y,t,t,x)'])
>>> debug_execute(gc.decompose, ['angle_bisector_property_equal_angle(T,t,y,x)'])
>>> debug_execute(gc.decompose, ['incenter_of_triangle_property_angle_bisector(H,t,T,x,M,a,N,y)'])
>>> debug_execute(gc.decompose, ['incenter_of_triangle_determination_angle_bisector(H,i,j,T,x,M,a,N,y)'])
>>> debug_execute(gc.decompose, ['triangle_determination(T,x,M,a,N,y)'])
>>> debug_execute(gc.decompose, ['angle_bisector_determination_angle_equal(N,j,a,y)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(a,j,j,y)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(N,a,j,y)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(a,j)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(d,a,j,a)'])
>>> debug_execute(gc.decompose, ['parallel_property_angle_equal(d,j,a)'])
>>> debug_execute(gc.decompose, ['parallel_determination_angle_equal(d,j,n)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(d,n,j,n)'])
>>> debug_execute(gc.decompose, ['perpendicular_between_line_property_angle(j,n)'])
>>> debug_execute(gc.decompose, ['orthocenter_of_triangle_property_perpendicular(H,j,N,m,P,n,M,a)'])
>>> debug_execute(gc.decompose, ['orthocenter_of_triangle_property_multiple_forms(H,M,a,N,m,P,n)'])
>>> debug_execute(gc.decompose, ['angle_bisector_determination_angle_equal(M,i,x,a)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(x,i,i,a)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(M,x,i,a)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(i,a,c,a)'])
>>> debug_execute(gc.decompose, ['parallel_property_angle_equal(i,c,a)'])
>>> debug_execute(gc.decompose, ['parallel_determination_angle_equal(i,c,m)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(i,m,c,m)'])
>>> debug_execute(gc.decompose, ['perpendicular_between_line_property_angle(i,m)'])
>>> debug_execute(gc.decompose, ['orthocenter_of_triangle_property_perpendicular(H,i,M,a,N,m,P,n)'])
>>> debug_execute(gc.decompose, ['orthocenter_of_triangle_property_multiple_forms(H,P,n,M,a,N,m)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(n,d)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(d,n,n,d)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_property_angle_equal(C,d,X,n,M,a,A,d,X,n,M,k)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_property_multiple_forms(M,a,C,d,X,n,M,k,A,d,X,n)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_property_multiple_forms(X,n,M,a,C,d,X,n,M,k,A,d)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_determination_asa(X,n,M,a,C,d,X,n,M,k,A,d)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(n,a,k,n)'])
>>> debug_execute(gc.decompose, ['triangle_determination(X,d,A,k,M,n)'])
>>> debug_execute(gc.decompose, ['triangle_determination(X,n,M,a,C,d)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(n,k)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(a,n)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(a,n,n,k)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_property_angle_equal(C,a,M,n,P,g,A,k,M,n,P,p)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_determination_sss(C,a,M,n,P,g,A,k,M,n,P,p)'])
>>> debug_execute(gc.decompose, ['triangle_determination(A,p,P,n,M,k)'])
>>> debug_execute(gc.decompose, ['triangle_determination(C,a,M,n,P,g)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(M,P,M,P)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(C,M,A,M)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(m,c)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(c,m,m,c)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_property_angle_equal(A,c,Y,m,N,l,D,c,Y,m,N,a)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_property_multiple_forms(N,l,A,c,Y,m,N,a,D,c,Y,m)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_property_multiple_forms(Y,m,N,l,A,c,Y,m,N,a,D,c)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_determination_asa(Y,m,N,l,A,c,Y,m,N,a,D,c)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(m,l,a,m)'])
>>> debug_execute(gc.decompose, ['triangle_determination(Y,c,D,a,N,m)'])
>>> debug_execute(gc.decompose, ['triangle_determination(Y,m,N,l,A,c)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(m,a)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(l,m)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(l,m,m,a)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_property_angle_equal(A,l,N,m,P,p,D,a,N,m,P,h)'])
>>> debug_execute(gc.decompose, ['mirror_congruent_triangle_determination_sss(A,l,N,m,P,p,D,a,N,m,P,h)'])
>>> debug_execute(gc.decompose, ['triangle_determination(D,h,P,m,N,a)'])
>>> debug_execute(gc.decompose, ['triangle_determination(A,l,N,m,P,p)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(A,N,D,N)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(N,P,N,P)'])
>>> debug_execute(gc.decompose, ['point_on_circle_determination_concyclic(Φ,F,B,E,T)'])
>>> debug_execute(gc.decompose, ['concyclic_between_points_determination_inscribed_angle_sum(F,e,B,f,E,x,T,y)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_point_on_circle(Φ,F,e,B,f,E,p)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_point_on_circle(Φ,E,p,F,e,B,f)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_point_on_circle(Φ,B,f,E,p,F,e)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_multiple_forms(Φ,E,p,F,e,B,f)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_multiple_forms(Φ,B,f,E,p,F,e)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(F,e,B,f,E,p)'])
>>> debug_execute(gc.decompose, ['triangle_determination(F,e,B,f,E,p)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(l,y,x,y)'])
>>> debug_execute(gc.decompose, ['parallel_property_angle_equal(l,x,y)'])
>>> debug_execute(gc.decompose, ['parallel_property_multiple_forms(x,l)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(N,l,a,y)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(a,l)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(N,l,A,c,D,a)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(a,y)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(y,a,k,a)'])
>>> debug_execute(gc.decompose, ['parallel_property_angle_equal(y,k,a)'])
>>> debug_execute(gc.decompose, ['concyclic_between_points_property_inscribed_angle_equal(B,w,A,c,D,e,F,p)'])
>>> debug_execute(gc.decompose, ['concyclic_between_points_determination_same_circle(Γ,B,A,D,F)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(D,c,a,w)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(D,a,K,v,A,c)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(D,w,B,v,K,a)'])
>>> debug_execute(gc.decompose, ['triangle_determination(D,a,K,v,A,c)'])
>>> debug_execute(gc.decompose, ['triangle_determination(D,w,B,v,K,a)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(w,v,v,c)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(D,w,B,v,A,c)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(D,w,B,v,A,c)'])
>>> debug_execute(gc.decompose, ['triangle_determination(D,w,B,v,A,c)'])
>>> debug_execute(gc.decompose, ['perpendicular_bisector_property_distance_equal(a,v,B,A,D)'])
>>> debug_execute(gc.decompose, ['perpendicular_bisector_property_multiple_forms(a,v,A,B)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(p,f)'])
>>> debug_execute(gc.decompose, ['concyclic_between_points_property_inscribed_angle_sum(B,u,C,d,A,p,E,f)'])
>>> debug_execute(gc.decompose, ['concyclic_between_points_determination_same_circle(Ω,B,C,A,E)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(C,u,a,d)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(B,u,C,a,K,v)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(A,v,K,a,C,d)'])
>>> debug_execute(gc.decompose, ['triangle_determination(B,u,C,a,K,v)'])
>>> debug_execute(gc.decompose, ['triangle_determination(A,v,K,a,C,d)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(d,v,v,u)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(C,d,A,v,B,u)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(C,d,A,v,B,u)'])
>>> debug_execute(gc.decompose, ['triangle_determination(C,d,A,v,B,u)'])
>>> debug_execute(gc.decompose, ['perpendicular_bisector_property_distance_equal(a,v,A,B,C)'])
>>> debug_execute(gc.decompose, ['perpendicular_between_line_property_angle(v,a)'])
>>> debug_execute(gc.decompose, ['perpendicular_between_line_property_angle(a,v)'])
>>> debug_execute(gc.decompose, ['perpendicular_between_line_property_multiple_forms(a,v)'])
>>> debug_execute(gc.decompose, ['perpendicular_bisector_property_perpendicular_between_line(a,v,A,B)'])
>>> debug_execute(gc.decompose, ['perpendicular_bisector_determination_center_line_and_common_chord(Ω,Γ,M,N,a,A,B,v)'])
>>> debug_execute(gc.decompose, ['parallel_determination_angle_equal(x,l,p)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(x,p,l,p)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(p,l)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(p,x)'])
>>> debug_execute(gc.decompose, ['parallel_determination_angle_equal(y,k,p)'])
>>> debug_execute(gc.decompose, ['equal_angle_determination_algebraic(y,p,k,p)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(D,c,a,h)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(A,p,l,c)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(A,d,k,p)'])
>>> debug_execute(gc.decompose, ['line_property_angle_addition(C,g,a,d)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(y,p,p,l)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(N,y,F,p,A,l)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(N,y,F,p,A,l)'])
>>> debug_execute(gc.decompose, ['triangle_determination(N,y,F,p,A,l)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(N,F,N,A)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(l,c,c,a)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(N,l,A,c,D,a)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(N,l,A,c,D,a)'])
>>> debug_execute(gc.decompose, ['triangle_determination(N,l,A,c,D,a)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(N,A,N,D)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Γ,N,F)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Γ,N,D)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Γ,N,A)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(k,p,p,x)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(M,k,A,p,E,x)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(M,k,A,p,E,x)'])
>>> debug_execute(gc.decompose, ['triangle_determination(M,k,A,p,E,x)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(M,A,M,E)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(a,d,d,k)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(M,a,C,d,A,k)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(M,a,C,d,A,k)'])
>>> debug_execute(gc.decompose, ['triangle_determination(M,a,C,d,A,k)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(M,C,M,A)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Ω,M,E)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Ω,M,A)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Ω,M,C)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(g,a,a,h)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(P,g,C,a,D,h)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(P,g,C,a,D,h)'])
>>> debug_execute(gc.decompose, ['triangle_determination(P,g,C,a,D,h)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(P,C,P,D)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(p,c,c,h)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(P,p,A,c,D,h)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(P,p,A,c,D,h)'])
>>> debug_execute(gc.decompose, ['triangle_determination(P,p,A,c,D,h)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(P,A,P,D)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(g,d,d,p)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(P,g,C,d,A,p)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(P,g,C,d,A,p)'])
>>> debug_execute(gc.decompose, ['triangle_determination(P,g,C,d,A,p)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(P,C,P,A)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Δ,P,D)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Δ,P,A)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Δ,P,C)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_point_on_circle(Δ,C,d,A,c,D,a)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_point_on_circle(Δ,D,a,C,d,A,c)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_point_on_circle(Δ,A,c,D,a,C,d)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_multiple_forms(Δ,A,c,D,a,C,d)'])
>>> debug_execute(gc.decompose, ['circumcircle_of_triangle_property_multiple_forms(Δ,C,d,A,c,D,a)'])
>>> debug_execute(gc.decompose, ['circumcenter_of_triangle_property_center_of_circle(P,Δ,C,d,A,c,D,a)'])
>>> debug_execute(gc.decompose, ['arc_property_central_angle_and_inscribed_angle(Φ,G,E,T,F,o,b,p,y)'])
>>> debug_execute(gc.decompose, ['arc_property_central_angle_and_inscribed_angle(Φ,G,T,F,E,b,q,x,p)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(y,x)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(a,d)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(x,a,l,a)'])
>>> debug_execute(gc.decompose, ['parallel_property_angle_equal(x,l,a)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(a,k)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(M,a,C,d,A,k)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(p,b)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(G,b,Q,p,E,o)'])
>>> debug_execute(gc.decompose, ['triangle_property_angle_sum(G,q,F,p,Q,b)'])
>>> debug_execute(gc.decompose, ['triangle_determination(G,b,Q,p,E,o)'])
>>> debug_execute(gc.decompose, ['triangle_determination(G,q,F,p,Q,b)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(q,b)'])
>>> debug_execute(gc.decompose, ['line_property_adjacent_complementary_angle(b,o)'])
>>> debug_execute(gc.decompose, ['equal_angle_property_algebraic(q,p,p,o)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_property_angle_equal(G,q,F,p,E,o)'])
>>> debug_execute(gc.decompose, ['isosceles_triangle_determination_distance_equal(G,q,F,p,E,o)'])
>>> debug_execute(gc.decompose, ['equal_distance_point_to_point_determination_algebraic(G,F,G,E)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Φ,G,E)'])
>>> debug_execute(gc.decompose, ['circle_property_radius_equal(Φ,G,F)'])
>>> debug_execute(gc.decompose, ['triangle_determination(G,q,F,p,E,o)'])

At any stage of the reasoning process, you can also call show_gc() and get_gc() to obtain the current state of the problem. Additionally, you can generate reasoning graphs of the solving process. The forward-solving process is stored internally in the solver as a hypergraph, where facts serve as hyper-nodes and the applied theorems as hyper-edges. The backward-solving process is stored internally as a composite graph: a standard graph with goals as nodes and applied theorems as edges, where each goal consists of a logical tree composed of sub-goals and logical expressions. You can plot the reasoning graphs for both forward and backward processes using the following methods:

>>> gc.draw_sg(save_path='../outputs/', file_format='png')

你将会得到类似的前向过程推理图：

以及后向过程推理图：

Contributing

We are committed to open-source and welcome contributions from the community. Fork our repository on GitHub and submit a pull request. We appreciate contributions of all sizes and are happy to assist newcomers to git with their pull requests. We look forward to having more people become part of this incredible journey.

Our bug reporting platform is available at here. We encourage you to report any issues you encounter.

Citation

To cite FormalGeo in publications use:

Zhang, X., Zhu, N., He, Y., Zou, J., Huang, Q., Jin, X., ... & Leng, T. (2024). FormalGeo: An Extensible Formalized Framework for Olympiad Geometric Problem Solving

A BibTeX entry for LaTeX users is:

@misc{arxiv2024formalgeo,
title={FormalGeo: An Extensible Formalized Framework for Olympiad Geometric Problem Solving},
author={Xiaokai Zhang and Na Zhu and Yiming He and Jia Zou and Qike Huang and Xiaoxiao Jin and Yanjun Guo and Chenyang Mao and Zhe Zhu and Dengfeng Yue and Fangzhen Zhu and Yang Li and Yifan Wang and Yiwen Huang and Runan Wang and Cheng Qin and Zhenbing Zeng and Shaorong Xie and Xiangfeng Luo and Tuo Leng},
year={2024},
eprint={2310.18021},
archivePrefix={arXiv},
primaryClass={cs.AI},
url={https://arxiv.org/abs/2310.18021}
}

FormalGeo is MIT licensed, so you are free to use it whatever you like, be it academic, commercial, creating forks or derivatives. If it is convenient for you, please cite FormalGeo when using it in your work.