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?Term1 @=< ?Term2

Succeeds if term Term1 is before or equal to Term2 in the standard ordering.
Term1
An arbitrary term.
Term2
An arbitrary term.

Description

Succeeds if term Term1 is before or equal to term Term2 in the standard order of terms (defined under compare/3).

See compare/3 for the definition of this standard ordering.

Modes and Determinism

Fail Conditions

Fails if Term1 comes after Term2.

Examples

   Success:
   X @=< 1.0.           (gives X = _g68)
   1.0 @=< 0.
   0 @=< "zero".
   same @=< same.
   diffa @=< diffb.
   [a|b] @=< [a,b].
   [a,b|X] @=< [a,b,c]. (gives X = _g90)
   f(100) @=< f(0,0).
   a(100) @=< b(1).
   Fail:
   1.0 @=< X.
   0 @=< 1.0.
   atom @=< "atom".
   a(1,2,3) @=< a(1,2,X).

See Also

compare / 3, @> / 2, @< / 2, @>= / 2