Theorem subbid-P3.41c.RC 337

Description: Inference Form of subbid-P3.41c 336. †

Hypotheses

Ref	Expression
subbid-P3.41c.RC.1	⊢ (𝜑 ↔ 𝜓)
subbid-P3.41c.RC.2	⊢ (𝜒 ↔ 𝜗)

Assertion

Ref	Expression
subbid-P3.41c.RC	⊢ ((𝜑 ↔ 𝜒) ↔ (𝜓 ↔ 𝜗))

Proof of Theorem subbid-P3.41c.RC

Step	Hyp	Ref	Expression
1		subbid-P3.41c.RC.1	. . . 4 ⊢ (𝜑 ↔ 𝜓)
2	1	ndtruei-P3.17 182	. . 3 ⊢ (⊤ → (𝜑 ↔ 𝜓))
3		subbid-P3.41c.RC.2	. . . 4 ⊢ (𝜒 ↔ 𝜗)
4	3	ndtruei-P3.17 182	. . 3 ⊢ (⊤ → (𝜒 ↔ 𝜗))
5	2, 4	subbid-P3.41c 336	. 2 ⊢ (⊤ → ((𝜑 ↔ 𝜒) ↔ (𝜓 ↔ 𝜗)))
6	5	ndtruee-P3.18 183	1 ⊢ ((𝜑 ↔ 𝜒) ↔ (𝜓 ↔ 𝜗))

Syntax hints:   ↔ wff-bi 104  ⊤wff-true 153

This theorem was proved from axioms:  ax-L1 11  ax-L2 12  ax-L3 13  ax-MP 14

This theorem depends on definitions:  df-bi-D2.1 107  df-and-D2.2 133  df-true-D2.4 155

This theorem is referenced by:  example-E6.01a  706  example-E6.02a  712