sets.lib
LIB "sets.lib"; list l =1,2,3; list j =2,3,4; Set N=l; Set M=j; N; ==> {3; 2; 1} ==> Set with 3 elements ==> M; ==> {4; 3; 2} ==> Set with 3 elements ==> N+M; ==> {1; 4; 3; 2} ==> Set with 4 elements ==>