theorem :: ZFMODEL1:17
for E being non empty set st E is being_a_model_of_ZF holds
( E is epsilon-transitive & ( for u, v being Element of E st ( for w being Element of E holds
( w in u iff w in v ) ) holds
u = v ) & ( for u, v being Element of E holds {u,v} in E ) & ( for u being Element of E holds union u in E ) & ex u being Element of E st
( u <> {} & ( for v being Element of E st v in u holds
ex w being Element of E st
( v c< w & w in u ) ) ) & ( for u being Element of E holds E /\ (bool u) in E ) & ( for H being ZF-formula
for f being Function of VAR,E st {(x. 0),(x. 1),(x. 2)} misses Free H & E,f |= All ((x. 3),(Ex ((x. 0),(All ((x. 4),(H <=> ((x. 4) '=' (x. 0)))))))) holds
for u being Element of E holds (def_func' (H,f)) .: u in E ) ) by Lm3, Th2, Th4, Th6, Th8, Th15;