let i, j be Integer; ( i > 0 & j > 0 implies Euclid-Function . (((dl. 0),(dl. 1)) --> (i,j)) = (dl. 0) .--> (i gcd j) )
assume
( i > 0 & j > 0 )
; Euclid-Function . (((dl. 0),(dl. 1)) --> (i,j)) = (dl. 0) .--> (i gcd j)
then
[(((dl. 0),(dl. 1)) --> (i,j)),((dl. 0) .--> (i gcd j))] in Euclid-Function
by Def2;
hence
Euclid-Function . (((dl. 0),(dl. 1)) --> (i,j)) = (dl. 0) .--> (i gcd j)
by FUNCT_1:1; verum