# 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

##</code><code>##

((a==b)and(c==d))or((e==f)and(g==h))