subtract : (* list -> * list -> * list)

SYNOPSIS
Computes the set-theoretic difference of two `sets'.

DESCRIBE
subtract l1 l2 returns a list consisting of those elements of l1 that do not appear in l2.

FAILURE
Never fails.

EXAMPLE
#subtract [1;2;3] [3;5;4;1];;
[2] : int list

#subtract [1;2;4;1] [4;5];;
[1; 2; 1] : int list

SEEALSO  setify,   set_equal,   union,   intersect

HOL  Kananaskis 0