Theorem triantru3 35504

Description: A wff is equivalent to its conjunctions with truths. (Contributed by Peter Mazsa, 30-Nov-2018.)

Hypotheses

Ref	Expression
triantru3.1	⊢ 𝜑
triantru3.2	⊢ 𝜓

Assertion

Ref	Expression
triantru3	⊢ (𝜒 ↔ (𝜑 ∧ 𝜓 ∧ 𝜒))

Proof of Theorem triantru3

Step	Hyp	Ref	Expression
1		triantru3.1	. . 3 ⊢ 𝜑
2	1	biantrur 533	. 2 ⊢ ((𝜓 ∧ 𝜒) ↔ (𝜑 ∧ (𝜓 ∧ 𝜒)))
3		triantru3.2	. . 3 ⊢ 𝜓
4	3	biantrur 533	. 2 ⊢ (𝜒 ↔ (𝜓 ∧ 𝜒))
5		3anass 1091	. 2 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) ↔ (𝜑 ∧ (𝜓 ∧ 𝜒)))
6	2, 4, 5	3bitr4i 305	1 ⊢ (𝜒 ↔ (𝜑 ∧ 𝜓 ∧ 𝜒))

Syntax hints:   ↔ wb 208   ∧ wa 398   ∧ w3a 1083

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 209  df-an 399  df-3an 1085

This theorem is referenced by:  eqvrelcoss  35856  eqvrelcoss3  35857