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Related theorems GIF version |
| Description: Define conjunction ('and') of 3 wff.s. Definition *4.34 of [WhiteheadRussell] p. 118. This abbreviation reduces the number of parentheses and emphasizes that the order of bracketing is not important by virtue of the associative law anass 336. |
| Ref | Expression |
|---|---|
| df-3an | ⊢ ((φ ∧ ψ ∧ χ) ↔ ((φ ∧ ψ) ∧ χ)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | wph | . . 3 wff φ | |
| 2 | wps | . . 3 wff ψ | |
| 3 | wch | . . 3 wff χ | |
| 4 | 1, 2, 3 | w3a 581 | . 2 wff (φ ∧ ψ ∧ χ) |
| 5 | 1, 2 | wa 196 | . . 3 wff (φ ∧ ψ) |
| 6 | 5, 3 | wa 196 | . 2 wff ((φ ∧ ψ) ∧ χ) |
| 7 | 4, 6 | wb 127 | 1 wff ((φ ∧ ψ ∧ χ) ↔ ((φ ∧ ψ) ∧ χ)) |
| Colors of variables: wff set class |
| This definition is referenced by: 3anass 585 3anrot 586 3ancoma 588 3simpa 591 3pm3.2i 603 3jca 604 im3an 605 bi3an 606 3imp 608 3exp 611 bi3and 636 an6 638 hb3an 707 otthg 1900 poss 2129 poirr 2133 po2nr 2135 po3nr 2136 dfwe2 2187 wefrc 2195 f1orn 2809 tz7.49c 2998 ndmoprass 3062 oaord 3149 nnmord 3189 sup2 4510 infxpidmlem7 4939 |