[ library(gfd) | Reference Manual | Alphabetic Index ]

<ConsistencyModule:> +ConX xor +ConY

One of the constraints ConX or ConY must be true.
ConX
Constraint
ConY
Constraint

Description

Equivalent to BX #= (ConX), BY #= (ConY), BX + BY #= 1

The two constraints are reified in such a way that one and only one must be true. ConX and ConY must be constraints that have a corresponding reified form.

ConsistencyModule is the optional module specification to give the consistency level for the propagation for this constraint: gfd_bc for bounds consistency, and gfd_gac for domain (generalised arc) consistency.

This constraint is implemented using Gecode's MiniModel's rel() for both integer and boolean expressions, with sub-expressions/constraints not supported by MiniModel factored out and posted as auxiliary constraints.

Modules

This predicate is sensitive to its module context (tool predicate, see @/2).

See Also

xor / 3, neg / 1, or / 2, and / 2, => / 2, <=> / 2, suspend : #\= / 2, ic : #\= / 2, fd : #\= / 2