SWI-Prolog -- succ/2

Documentation
- Reference manual
  - Built-in Predicates
    - Arithmetic
      - Special purpose integer arithmetic
        
        between/3
        
        succ/2
        
        plus/3
        
        divmod/4
        
        nth_integer_root_and_remainder/4
- Packages

Availability:built-in

succ(?Int1, ?Int2)

True if Int2 = Int1 + 1 and Int1 >= 0. At least one of the arguments must be instantiated to a natural number. This predicate raises the domain error not_less_than_zero if called with a negative integer. E.g. succ(X, 0) fails silently and succ(X, -1) raises a domain error.^{113The
behaviour to deal with natural numbers only was defined by Richard
O'Keefe to support the common count-down-to-zero in a natural way. Up to
5.1.8, succ/2
also accepted negative integers.}