Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > ILE Home > Th. List > pw0 | GIF version |
Description: Compute the power set of the empty set. Theorem 89 of [Suppes] p. 47. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Andrew Salmon, 29-Jun-2011.) |
Ref | Expression |
---|---|
pw0 | ⊢ 𝒫 ∅ = {∅} |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ss0b 3256 | . . 3 ⊢ (𝑥 ⊆ ∅ ↔ 𝑥 = ∅) | |
2 | 1 | abbii 2153 | . 2 ⊢ {𝑥 ∣ 𝑥 ⊆ ∅} = {𝑥 ∣ 𝑥 = ∅} |
3 | df-pw 3361 | . 2 ⊢ 𝒫 ∅ = {𝑥 ∣ 𝑥 ⊆ ∅} | |
4 | df-sn 3381 | . 2 ⊢ {∅} = {𝑥 ∣ 𝑥 = ∅} | |
5 | 2, 3, 4 | 3eqtr4i 2070 | 1 ⊢ 𝒫 ∅ = {∅} |
Colors of variables: wff set class |
Syntax hints: = wceq 1243 {cab 2026 ⊆ wss 2917 ∅c0 3224 𝒫 cpw 3359 {csn 3375 |
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-io 630 ax-5 1336 ax-7 1337 ax-gen 1338 ax-ie1 1382 ax-ie2 1383 ax-8 1395 ax-10 1396 ax-11 1397 ax-i12 1398 ax-bndl 1399 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-tru 1246 df-nf 1350 df-sb 1646 df-clab 2027 df-cleq 2033 df-clel 2036 df-nfc 2167 df-v 2559 df-dif 2920 df-in 2924 df-ss 2931 df-nul 3225 df-pw 3361 df-sn 3381 |
This theorem is referenced by: p0ex 3939 |
Copyright terms: Public domain | W3C validator |