for a being object
for S being non empty non void ManySortedSign
for s being SortSymbol of S
for X being V5() ManySortedSet of the carrier of S
for x being Element of X . s
for t being Element of (Free (S,X))
for C being context of x st X is non-trivial & the_sort_of t = s holds
card (Coim (t,a)) c= card (Coim ((C -sub t),a))