Bools

class BoolCell(value=None)

3-valued logic (T, F, U) (U)ndefined means (T v F) ^ -(T ^ F)

static coerce(value)

Coerces a Bool, None, or int into Bit/Propositional form. If value is an int, must be -1, 0, or 1.

Note

T, F, and U can be used in place of True, False, and 'UNKNOWN', respectively.

Parameters:value (bool, int) – The value to coerce Returns:BoolCell Raises:CellConstructionFailure, CoercionFailure

>>> f1 = BoolCell.coerce(0)
>>> f1
False
>>> f2 = BoolCell.coerce(F)
>>> f2
False
>>> t1 = BoolCell.coerce(1)
>>> t1
True
>>> t2 = BoolCell.coerce(T)
>>> t2
True

is_entailed_by(other)

Returns True if the other is as or more specific than self

Parameters:other (BoolCell, bool, int) – The BoolCell or coercible value that may entail self Returns:bool Raises:CellConstructionFailure, CoercionFailure

>>> x = BoolCell(T)
>>> y = BoolCell(F)
>>> z = BoolCell(U)
>>> x.is_entailed_by(U)
False
>>> y.is_entailed_by(F)
True
>>> y.is_entailed_by(U)
False
>>> z.is_entailed_by(x)
True

entails(other)

Inverse of is_entailed_by. Returns True if self is as or more specific than other.

Parameters:other (BoolCell, bool, int) – The BoolCell or coercible value to check if it is entailed by self Returns:bool Raises:CellConstructionFailure, CoercionFailure

>>> x = BoolCell(T)
>>> y = BoolCell(F)
>>> z = BoolCell(U)
>>> x.entails(T)
True
>>> x.entails(U)
True
>>> y.entails(T)
False
>>> y.entails(F)
True
>>> z.entails(U)
True
>>> z.entails(F)
False

is_contradictory(other)

Determines if two cells are contradictory. Returns a boolean.

Parameters:other (BoolCell, bool, int) – The BoolCell or value that may contradict self. Returns:bool Raises:CellConstructionFailure, CoercionFailure

>>> x = BoolCell(T)
>>> y = BoolCell(F)
>>> z = BoolCell(U)
>>> x.is_contradictory(y)
True
>>> y.is_contradictory(x)
True
>>> z.is_contradictory(x)
False
>>> z.is_contradictory(y)
False
>>> z.is_contradictory(U)
False

to_json()

Returns JSON representation of BoolCell

from_json(other)

Initializes from JSON representation

is_equal(other)

Tests whether two Cells are equal. Returns a boolean.

Parameters:other (BoolCell, bool, int) – BoolCell or coercible value to be tested Returns:bool Raises:CoercionFailure

>>> x = BoolCell(T)
>>> y = BoolCell(F)
>>> x.is_equal(x)
True
>>> x.is_equal(T)
True
>>> y.is_equal(x)
False

merge(other)

Merges two BoolCells. A Contradiction is raised if the two BoolCells are contradictory.

Parameters:other (BoolCell, bool, int) – BoolCell or coerce-able value to be merged Returns:BoolCell Raises:CellConstructionFailure, CoercionFailure, Contradiction

>>> v = BoolCell(U)
>>> w = BoolCell(U)
>>> z = BoolCell(U)
>>> v.merge(T)
True
>>> z.merge(F)
False
>>> w.merge(U)
'UNKNOWN'