# user adds first clause [==,a,b] # implies if a == b, prefix notation # and a new clause [and,[==,a,b],[==,c,d]] # or a new clause [or,[and,[==,a,b],[==,c,d]],[==,e,f]] # and a new clause [or,[and,[==,a,b],[==,c,d]],[and,[==,e,f],[==,g,h]] etc