prevision 0.0.1

A Visualization Tool for Computations of Probabilistic Term Rewriting

PReVision

A Probabilistic Term Rewrite System Visualization tool.

Description

PReVision parses a probabilistic Term Rewrite System as specified here and evaluates the corresponding computation tree in various ways, and gives a visualization of the evaluation.

Features

PReVision offers a range of features for evaluating and visualizing probabilistic term rewrite systems. All features include visualization support (DOT file or PNG images), with results saved in a specified folder.

Visualization

• Full computation tree generation: Does neither resolve probabilities nor non-determinism.
• Layer-by-layer evaluation: Resolve non-determinism for a specified i-th layer resulting in possibly multiple trees.
• Probability-resolved evaluation: Resolve probabilities for a specified i-th layer resulting in possibly multiple trees.
• Random path computation: Resolve both non-determinism and probabilities generating a pseudo-random path of the computation tree.

Evaluation

• Multiple evaluation strategies: Use various evaluation strategies, including outermost, innermost, and leftmost/rightmost redex selection.
• Derscribe Evaluationstrategies + example

Dependencies

pydot-3.0.4

• graphviz

Installation

# will be specified later

Usage

usage: prevision [-h] [-p | -q] [-d | -b] [-t <int>] [-s <str>] [-f <str>] [-o <path>] <path> <term>

PReVision: A Probabilistic Term Rewrite System Visualization tool.

positional arguments:
  <path>                      path to the input file (txt)
  <term>                      starting term from which the computation tree is expanded

options:
  -h, --help                  show this help message and exit
  -p, --probabilistic         shows probabilistic paths in the tree (default)
  -q, --non-probabilistic     resolves probabilistic paths by creating new trees for each
  -d, --deterministic         resolves non-deterministic paths by creating new trees for each
  -b, --non-deterministic     shows non-deterministic paths in the tree (default)
  -t <int>, --depth <int>     the maximum depth of the computation tree (default: 3)
  -s <str>, --strategy <str>  evaluation strategy to filter reducible expressions (default: 'full')
  -f <str>, --format <str>    the output format (default: 'png')
  -o <path>, --output <path>  output directory for results (default: './')

notes:
  - the following options are mutually exclusive:
    * '--deterministic' (-d) and '--non-deterministic' (-b)
    * '--probabilistic' (-p) and '--non-probabilistic' (-q)
  - available evaluation strategies:
    * 'full'    computes the entire computation tree
    * 'o'       evaluates all outermost reducible expressions at each step
    * 'i'       evaluates all innermost reducible expressions at each step
    * 'lo'      evaluates only the leftmost outermost reducible expression
    * 'ro'      evaluates only the rightmost outermost reducible expression
    * 'li'      evaluates only the leftmost innermost reducible expression
    * 'ri'      evaluates only the rightmost innermost reducible expression
  - available formats:
    * ['canon', 'cmap', 'cmapx', 'cmapx_np', 'dia', 'dot', 'fig', 'gd',
       'gd2', 'gif', 'hpgl', 'imap', 'imap_np', 'ismap', 'jpe', 'jpeg',
       'jpg', 'mif', 'mp', 'pcl', 'pdf', 'pic', 'plain', 'plain-ext',
       'png', 'ps', 'ps2', 'svg', 'svgz', 'vml', 'vmlz', 'vrml', 'vtx',
       'wbmp', 'xdot', 'xlib']
  - example:
    * prevision -pd -t 3 -o './results' -s 'lo' input_file.txt (s (s x))
    * description:
        Resolves non-determinisms by building (potentially) multiple
        deterministic trees. Shows probabilistic paths. Only
        evaluates the leftmost outermost redex. The generated trees have a
        maximum depth of 3. Results will be saved in the './results'
        directory as PNG images.

License

• will be specified later

Contact

Reach us:

David Weber, Author

Email: [e-mail] GitHub: davidpweber

Jan-Christoph Kassing, Supervisor

Email: [e-mail] GitHub: ?

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