property::implies
-- test
whether one property implies anotherproperty::implies(
prop_1, prop_2)
tries to
decide whether prop_1
implies prop_2
or its
converse.
property::implies(prop_1, prop_2)
prop_1, prop_2 |
- | any properties |
TRUE
, FALSE
, or UNKNOWN
is
, assume
, property::simpex
, bool
property
for an overview of all properties.TRUE
if prop_2
can be
inferred from prop_1
, and FALSE
if not prop_2
can
be inferred from prop_1
. The result is UNKNOWN
if neither implication could
be proved; this may be because neither holds, or because the property
mechanism is too weak to find a proof.Every positive integer is positive:
>> property::implies(Type::PosInt, Type::Positive)
TRUE
Some positive numbers are positive integers, and some are not:
>> property::implies(Type::Positive, Type::PosInt)
UNKNOWN
No positive number is a negative integer:
>> property::implies(Type::Positive, Type::NegInt)
FALSE