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| Mirrors > Home > ILE Home > Th. List > dcne | GIF version | ||
| Description: Decidable equality expressed in terms of ≠. Basically the same as df-dc 847. (Contributed by Jim Kingdon, 14-Mar-2020.) |
| Ref | Expression |
|---|---|
| dcne | ⊢ (DECID 𝐴 = 𝐵 ↔ (𝐴 = 𝐵 ∨ 𝐴 ≠ 𝐵)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-dc 847 | . 2 ⊢ (DECID 𝐴 = 𝐵 ↔ (𝐴 = 𝐵 ∨ ¬ 𝐴 = 𝐵)) | |
| 2 | df-ne 2421 | . . 3 ⊢ (𝐴 ≠ 𝐵 ↔ ¬ 𝐴 = 𝐵) | |
| 3 | 2 | orbi2i 774 | . 2 ⊢ ((𝐴 = 𝐵 ∨ 𝐴 ≠ 𝐵) ↔ (𝐴 = 𝐵 ∨ ¬ 𝐴 = 𝐵)) |
| 4 | 1, 3 | bitr4i 187 | 1 ⊢ (DECID 𝐴 = 𝐵 ↔ (𝐴 = 𝐵 ∨ 𝐴 ≠ 𝐵)) |
| Colors of variables: wff set class |
| This proof depends on syntax axioms: ¬ wn 3 ↔ wb 105 ∨ wo 720 DECID wdc 846 = wceq 1402 ≠ wne 2420 |
| This proof depends on axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-io 721 |
| This proof depends on definitions: df-bi 117 df-dc 847 df-ne 2421 |
| This theorem is used by: updjudhf 7420 pr1or2 7541 zdceq 9725 nn0lt2 9732 xlesubadd 10296 qdceq 10690 ccat1st1st 11425 swrdccatin1 11513 xrmaxadd 12046 fsumdvds 12628 nn0seqcvgd 12838 pcxnn0cl 13112 pcxqcl 13114 pcge0 13115 pcdvdsb 13122 pcneg 13127 pcdvdstr 13129 pcgcd1 13130 pc2dvds 13132 pcz 13134 pcprmpw2 13135 pcaddlem 13141 pcadd 13142 pcmpt 13145 qexpz 13154 4sqlem19 13211 prmlem1a 13244 lgsneg1 16310 lgsdirprm 16319 lgsdir 16320 lgsne0 16323 lgsdirnn0 16332 lgsdinn0 16333 2sqlem9 16409 upgr1een 16531 usgr1e 16648 eupth2lem3lem3fi 16877 eupth2lem3lem7fi 16881 tridceq 17273 |
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