At: member col subst 2 3
1. c: Label
Collection(Term)
2. r: rel()
3. r': rel()
4. as: (Label
Term) List
5. 1of(unzip(as)) = rel_vars(r)
6. 
i:
. i < ||as|| 
2of(as[i]) 
c(1of(as[i]))
7. r' = rel_subst(as;r)
as = zip(rel_vars(r);2of(unzip(as)))
By:
SubstFor rel_vars(r) 0
THEN
RWW "zip_unzip" 0
Generated subgoals:None
About:
