Synopsis

tt (truth table) is a library aiming to provide a toolkit for working with Boolean expressions and truth tables. Please see the project site for guides and documentation.

Installation

tt is tested on the latest three major versions of CPython. You can get the latest release from PyPI with:

pip install ttable

Features

Parse expressions:

>>> from tt import BooleanExpression
>>> b = BooleanExpression('A impl not (B nand C)')
>>> b.tokens
['A', 'impl', 'not', '(', 'B', 'nand', 'C', ')']
>>> print(b.tree)
impl
`----A
`----not
     `----nand
          `----B
          `----C

Evaluate expressions:

>>> b = BooleanExpression('(A /\\ B) -> (C \\/ D)')
>>> b.evaluate(A=1, B=1, C=0, D=0)
False
>>> b.evaluate(A=1, B=1, C=1, D=0)
True

Interact with expression structure:

>>> b = BooleanExpression('(A and ~B and C) or (~C and D) or E')
>>> b.is_dnf
True
>>> for clause in b.iter_dnf_clauses():
...     print(clause)
...
A and ~B and C
~C and D
E

Apply expression transformations:

>>> from tt import to_primitives, to_cnf
>>> to_primitives('A xor B')
<BooleanExpression "(A and not B) or (not A and B)">
>>> to_cnf('(A nand B) impl (C or D)')
<BooleanExpression "(A or C or D) and (B or C or D)">

Or create your own:

>>> from tt import tt_compose, apply_de_morgans, coalesce_negations, twice
>>> b = BooleanExpression('not (not (A or B))')
>>> f = tt_compose(apply_de_morgans, twice)
>>> f(b)
<BooleanExpression "not not A or not not B">
>>> g = tt_compose(f, coalesce_negations)
>>> g(b)
<BooleanExpression "A or B">

Exhaust SAT solutions:

>>> b = BooleanExpression('~(A or B) xor C')
>>> for sat_solution in b.sat_all():
...     print(sat_solution)
...
A=0, B=0, C=0
A=1, B=0, C=1
A=0, B=1, C=1
A=1, B=1, C=1

Find just a few:

>>> with b.constrain(A=1):
...     for sat_solution in b.sat_all():
...         print(sat_solution)
...
A=1, B=0, C=1
A=1, B=1, C=1

Or just one:

>>> b.sat_one()
<BooleanValues [A=0, B=0, C=0]>

Build truth tables:

>>> from tt import TruthTable
>>> t = TruthTable('A iff B')
>>> print(t)
+---+---+---+
| A | B |   |
+---+---+---+
| 0 | 0 | 1 |
+---+---+---+
| 0 | 1 | 0 |
+---+---+---+
| 1 | 0 | 0 |
+---+---+---+
| 1 | 1 | 1 |
+---+---+---+

And much more!

License

tt uses the MIT License.