| Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
| Mirrors > Home > ILE Home > Th. List > psseq2d | GIF version | ||
| Description: An equality deduction for the proper subclass relationship. (Contributed by NM, 9-Jun-2004.) |
| Ref | Expression |
|---|---|
| psseq1d.1 | ⊢ (𝜑 → 𝐴 = 𝐵) |
| Ref | Expression |
|---|---|
| psseq2d | ⊢ (𝜑 → (𝐶 ⊊ 𝐴 ↔ 𝐶 ⊊ 𝐵)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | psseq1d.1 | . 2 ⊢ (𝜑 → 𝐴 = 𝐵) | |
| 2 | psseq2 3032 | . 2 ⊢ (𝐴 = 𝐵 → (𝐶 ⊊ 𝐴 ↔ 𝐶 ⊊ 𝐵)) | |
| 3 | 1, 2 | syl 14 | 1 ⊢ (𝜑 → (𝐶 ⊊ 𝐴 ↔ 𝐶 ⊊ 𝐵)) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ↔ wb 98 = wceq 1243 ⊊ wpss 2918 |
| This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 99 ax-ia2 100 ax-ia3 101 ax-in1 544 ax-in2 545 ax-5 1336 ax-7 1337 ax-gen 1338 ax-ie1 1382 ax-ie2 1383 ax-8 1395 ax-11 1397 ax-4 1400 ax-17 1419 ax-i9 1423 ax-ial 1427 ax-i5r 1428 ax-ext 2022 |
| This theorem depends on definitions: df-bi 110 df-nf 1350 df-sb 1646 df-clab 2027 df-cleq 2033 df-clel 2036 df-ne 2206 df-in 2924 df-ss 2931 df-pss 2933 |
| This theorem is referenced by: psseq12d 3038 |
| Copyright terms: Public domain | W3C validator |