py-aiger-past-ltl

Library for generating (p)ast (t)ense (l)inear (t)emporal (l)ogic monitors as aiger circuits. Builds on the py-aiger project.

Table of Contents

• Installation
• Usage

Installation

If you just need to use aiger_ptltl, you can just run:

$ pip install py-aiger-ptltl

For developers, note that this project uses the poetry python package/dependency management tool. Please familarize yourself with it and then run:

$ poetry install

Usage

The primary entry point for using aiger_ptltl is the PTLTLExpr class which is a simple extension of aiger.BoolExpr to support the temporal operators, historically, past (once), (variant) yesterday, and since.

import aiger_ptltl as ptltl

# Atomic Propositions
x = ptltl.atom('x')
y = ptltl.atom('y')
z = ptltl.atom('z')

# Propositional logic
expr1 = ~x
expr2 = x & (y | z)
expr3 = (x & y) | ~z
expr4 = ~(x & y & z)

# Temporal Logic
expr5 = x.historically()  #  (H x) ≡ x has held for all previous cycles (inclusive).
expr6 = x.once()  #  (P x) ≡ x once held in a past cycle (inclusive).
expr7 = x.vyest()  #  (Z x) ≡ x held in the previous cycle (true at time = 0).
expr8 = x.yest()  #  (Y x) ≡ x held in the previous cycle (false at time = 0).
expr9 = x.since(y)  #  [x S y] ≡ x has held since the cycle after y last held.

# Composition
expr9 = expr7.since(expr9.vyest().vyest())