let R be Relation; for C being Completion of R holds R,C are_equivalent
let C be Completion of R; R,C are_equivalent
let a, b be object ; REWRITE1:def 26 ( a,b are_convertible_wrt R iff a,b are_convertible_wrt C )
( a,b are_convertible_wrt R iff a,b are_convergent_wrt C )
by Def28;
hence
( a,b are_convertible_wrt R iff a,b are_convertible_wrt C )
by Def23, Th37; verum