Theorem pm3.21 233

Description: Join antecedents with conjunction. Theorem *3.21 of [WhiteheadRussell] p. 111.

Assertion

Ref	Expression
pm3.21	⊢ (φ → (ψ → (ψ ∧ φ)))

Proof of Theorem pm3.21

Step	Hyp	Ref	Expression
1		pm3.2 232	. 2 ⊢ (ψ → (φ → (ψ ∧ φ)))
2	1	com12 13	1 ⊢ (φ → (ψ → (ψ ∧ φ)))

Syntax hints:   → wi 2   ∧ wa 196

This theorem is referenced by:  ancr 243  anc2r 249  dedlemb 570  chrelat2 5758

This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6

This theorem depends on definitions:  df-bi 128  df-an 198

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