5.346. sign_of

DESCRIPTIONLINKS
Origin

Arithmetic.

Constraint

𝚜𝚒𝚐𝚗_𝚘𝚏(𝚂,𝚇)

Usual name

𝚜𝚒𝚐𝚗

Arguments
𝚂𝚍𝚟𝚊𝚛
𝚇𝚍𝚟𝚊𝚛
Restrictions
𝚂-1
𝚂1
Purpose

According to the value of the first variable 𝚂, restrict the sign of the second variable 𝚇:

  • When 𝚂=-1, 𝚇 should be negative (i.e., 𝚇<0).

  • When 𝚂=0, 𝚇 is also equal to 0.

  • When 𝚂=+1, 𝚇 should be positive (i.e., 𝚇>0).

Example
(-1,-8)
(0,0)
(1,8)
  • The first 𝚜𝚒𝚐𝚗_𝚘𝚏 constraint holds since 𝚂=-1 and 𝚇=-8 is negative.

  • The second 𝚜𝚒𝚐𝚗_𝚘𝚏 constraint holds since 𝚂=0 and 𝚇=0 is neither negative, neither positive.

  • The second 𝚜𝚒𝚐𝚗_𝚘𝚏 constraint holds since 𝚂=+1 and 𝚇=8 is positive.

Typical
𝚂0
𝚇0
Arg. properties

Functional dependency: 𝚂 determined by 𝚇.

See also

implies: 𝚜𝚊𝚖𝚎_𝚜𝚒𝚐𝚗, 𝚣𝚎𝚛𝚘_𝚘𝚛_𝚗𝚘𝚝_𝚣𝚎𝚛𝚘.

Keywords

constraint arguments: binary constraint, pure functional dependency.

constraint type: predefined constraint, arithmetic constraint.

filtering: arc-consistency.

modelling: functional dependency.