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| Mirrors > Home > NFE Home > Th. List > sbcid | GIF version | ||
| Description: An identity theorem for substitution. See sbid 1922. (Contributed by Mario Carneiro, 18-Feb-2017.) |
| Ref | Expression |
|---|---|
| sbcid | ⊢ ([̣x / x]̣φ ↔ φ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sbsbc 3051 | . 2 ⊢ ([x / x]φ ↔ [̣x / x]̣φ) | |
| 2 | sbid 1922 | . 2 ⊢ ([x / x]φ ↔ φ) | |
| 3 | 1, 2 | bitr3i 242 | 1 ⊢ ([̣x / x]̣φ ↔ φ) |
| Colors of variables: wff setvar class |
| Syntax hints: ↔ wb 176 [wsb 1648 [̣wsbc 3047 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1546 ax-5 1557 ax-17 1616 ax-9 1654 ax-8 1675 ax-11 1746 ax-ext 2334 |
| This theorem depends on definitions: df-bi 177 df-an 360 df-ex 1542 df-sb 1649 df-clab 2340 df-cleq 2346 df-clel 2349 df-sbc 3048 |
| This theorem is referenced by: (None) |
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