Initializing help system before first use

implies

implies

Purpose
This composite constraint states an implication between two constraints C1 and C2 ( C1 ⇒ C2), which are not individually posted. The satisfaction of the resulting constraint is given by the following truth table: 
  C1     C2       C1 implies C2
  --------------------------
  false  false    true
  false  true     true
  true   false    false
  true   true     true

Synopsis
function implies(C1:cpctr, C2:cpctr) : cpctr
Arguments
C1 
the left member constraint of the implication
C2 
the right member constraint of the implication
Return value
An implication constraint over C1 and C2
Example
The following example shows how to use the implication constraint 
model "Logical constraints"
 uses "kalis"

! Default bounds for all variables
 setparam("KALIS_DEFAULT_LB", 0); setparam("KALIS_DEFAULT_UB", 5)

 declarations
  A, B, C, D, E: cpctr
  x,y,z,b: cpvar
 end-declarations

 setname(b, "b"); setname(x, "x")
 setname(y, "y"); setname(z, "z")
 b <= 1

! Definition of constraints (without posting)
 A:= x >= y + 5 + z + b
 B:= b = 1
 C:= all_different({x, y, z})    ! Cannot be used with 'equiv'
 D:= y <= z
 E:= distance(y,z) <= 2

 writeln("Original domains: ", b, " ", x, " ", y, " ", z)

! If x, y and z are all different then b equals 1 (C=>B),
! if b equals 1 then x, y and z are all different (B=>C).
 implies(C, B)
 implies(B, C)

! E<=>B: b equals 1 if and only if |y-z| <= 2
 equiv(E, B)

! A<=>D: x >= y + 5 + z + b if and only if y <= z
 equiv(A, D)

 writeln("With constraints: ", b, " ", x, " ", y, " ", z)

 while (cp_find_next_sol)
  writeln("Solution: ", b, " ", x, " ", y, " ", z)

end-model

Related topics
equiv and or

Parent Topic Constraints

© 2001-2019 Fair Isaac Corporation. All rights reserved. This documentation is the property of Fair Isaac Corporation (“FICO”). Receipt or possession of this documentation does not convey rights to disclose, reproduce, make derivative works, use, or allow others to use it except solely for internal evaluation purposes to determine whether to purchase a license to the software described in this documentation, or as otherwise set forth in a written software license agreement between you and FICO (or a FICO affiliate). Use of this documentation and the software described in it must conform strictly to the foregoing permitted uses, and no other use is permitted.