1 | 6. s: SimpleType 7. as: (Label Term) List 8. ds: Collection{i}(dec()) 9. da: Collection{i}(SimpleType) 10. de: sig() 11. a:SimpleType. a term_types(ds;da;de;y2) & a s term_types(ds;da;de;y1) 12. x:Label.
(x term_primed_vars(y1) @ term_primed_vars(y2)) 
( t:SimpleType. mk_dec(x, t) ds  t term_types(ds;da;de;apply_alist(as;x;x))) a:SimpleType.
a term_types(ds;da;de;term_subst2(as;y2)) & a s term_types(ds;da;de;term_subst2(as;y1)) |