Theorem an12 495

Description: Swap two conjuncts. Note that the first digit (1) in the label refers to the outer conjunct position, and the next digit (2) to the inner conjunct position. (Contributed by NM, 12-Mar-1995.)

Assertion

Ref	Expression
an12	⊢ ((𝜑 ∧ (𝜓 ∧ 𝜒)) ↔ (𝜓 ∧ (𝜑 ∧ 𝜒)))

Proof of Theorem an12

Step	Hyp	Ref	Expression
1		ancom 253	. . 3 ⊢ ((𝜑 ∧ 𝜓) ↔ (𝜓 ∧ 𝜑))
2	1	anbi1i 431	. 2 ⊢ (((𝜑 ∧ 𝜓) ∧ 𝜒) ↔ ((𝜓 ∧ 𝜑) ∧ 𝜒))
3		anass 381	. 2 ⊢ (((𝜑 ∧ 𝜓) ∧ 𝜒) ↔ (𝜑 ∧ (𝜓 ∧ 𝜒)))
4		anass 381	. 2 ⊢ (((𝜓 ∧ 𝜑) ∧ 𝜒) ↔ (𝜓 ∧ (𝜑 ∧ 𝜒)))
5	2, 3, 4	3bitr3i 199	1 ⊢ ((𝜑 ∧ (𝜓 ∧ 𝜒)) ↔ (𝜓 ∧ (𝜑 ∧ 𝜒)))

Syntax hints:   ∧ wa 97   ↔ wb 98

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101

This theorem depends on definitions:  df-bi 110

This theorem is referenced by:  an32  496  an13  497  an12s  499  an4  520  ceqsrexv  2674  rmoan  2739  2reuswapdc  2743  reuind  2744  2rmorex  2745  sbccomlem  2832  elunirab  3593  rexxfrd  4195  opeliunxp  4395  elres  4646  resoprab  5597  ov6g  5638  opabex3d  5748  opabex3  5749  xpassen  6304  distrnqg  6485  distrnq0  6557  rexuz2  8524  2clim  9822