Description: Injectivity of the block constructor under disjointness. suc11reg analogue: under disjointness, equal blocks force equal generators (on dom R ). (Contributed by Peter Mazsa, 16-Feb-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | disjimeceqbi2 | |- ( Disj R -> ( ( A e. dom R /\ B e. dom R ) -> ( [ A ] R = [ B ] R <-> A = B ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | disjimeceqim2 | |- ( Disj R -> ( ( A e. dom R /\ B e. dom R ) -> ( [ A ] R = [ B ] R -> A = B ) ) ) |
|
| 2 | eceq1 | |- ( A = B -> [ A ] R = [ B ] R ) |
|
| 3 | 2 | 2a1i | |- ( Disj R -> ( ( A e. dom R /\ B e. dom R ) -> ( A = B -> [ A ] R = [ B ] R ) ) ) |
| 4 | 1 3 | impbidd | |- ( Disj R -> ( ( A e. dom R /\ B e. dom R ) -> ( [ A ] R = [ B ] R <-> A = B ) ) ) |