let R be Relation; ( ( for a, b being set holds not a,b are_critical_wrt R ) implies R is locally-confluent )
assume A1:
for a, b being set holds not a,b are_critical_wrt R
; R is locally-confluent
let a, b, c be set ; REWRITE1:def 24 ( [a,b] in R & [a,c] in R implies b,c are_convergent_wrt R )
assume
( [a,b] in R & [a,c] in R )
; b,c are_convergent_wrt R
then A2:
b,c are_divergent<=1_wrt R
by Def10;
not b,c are_critical_wrt R
by A1;
hence
b,c are_convergent_wrt R
by A2, Def27; verum