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Mirrors > Home > NFE Home > Th. List > 3anbi13d | GIF version |
Description: Deduction conjoining and adding a conjunct to equivalences. (Contributed by NM, 8-Sep-2006.) |
Ref | Expression |
---|---|
3anbi12d.1 | ⊢ (φ → (ψ ↔ χ)) |
3anbi12d.2 | ⊢ (φ → (θ ↔ τ)) |
Ref | Expression |
---|---|
3anbi13d | ⊢ (φ → ((ψ ∧ η ∧ θ) ↔ (χ ∧ η ∧ τ))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 3anbi12d.1 | . 2 ⊢ (φ → (ψ ↔ χ)) | |
2 | biidd 228 | . 2 ⊢ (φ → (η ↔ η)) | |
3 | 3anbi12d.2 | . 2 ⊢ (φ → (θ ↔ τ)) | |
4 | 1, 2, 3 | 3anbi123d 1252 | 1 ⊢ (φ → ((ψ ∧ η ∧ θ) ↔ (χ ∧ η ∧ τ))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 176 ∧ w3a 934 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 |
This theorem depends on definitions: df-bi 177 df-an 360 df-3an 936 |
This theorem is referenced by: 3anbi3d 1258 ax11wdemo 1723 sfineq1 4527 spaccl 6287 spacind 6288 nchoicelem3 6292 |
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