theorem Th34: :: OSAFREE:34

for S being locally_directed OrderSortedSign
for X being non-empty ManySortedSet of S
for R being OSCongruence of ParsedTermsOSA X
for t1, t2 being Element of TS (DTConOSA X) holds
( t2 in OSClass (R,t1) iff OSClass (R,t1) = OSClass (R,t2) )