deffunc H₁( set ) -> set = (Den o,A) . (a +* i,$1);
ex f being Function st
( dom f = the Sorts of A . ((the_arity_of o) /. i) & ( for x being set st x in the Sorts of A . ((the_arity_of o) /. i) holds
f . x = H₁(x) ) ) from FUNCT_1:sch 3();
hence ex b₁ being Function st
( dom b₁ = the Sorts of A . ((the_arity_of o) /. i) & ( for x being set st x in the Sorts of A . ((the_arity_of o) /. i) holds
b₁ . x = (Den o,A) . (a +* i,x) ) ) ; :: thesis: verum