This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.

Metamath Proof Explorer

Theorem mullidd

Description: Identity law for multiplication. (Contributed by Mario Carneiro, 27-May-2016)

		Ref	Expression
	Hypothesis	addcld.1	$⊢ φ \to A \in ℂ$
	Assertion	mullidd	$⊢ φ \to 1 A = A$

Step	Hyp	Ref	Expression
1		addcld.1	$⊢ φ \to A \in ℂ$
2		mullid	$⊢ A \in ℂ \to 1 A = A$
3	1 2	syl	$⊢ φ \to 1 A = A$