Theorem 5m1e4

Description: 5 - 1 = 4. (Contributed by AV, 6-Sep-2021)

	Ref	Expression
Assertion	5m1e4	$$⊢5-1=4$$

Proof

Step	Hyp	Ref	Expression
1		4cn	$$⊢4\in ℂ$$
2		ax-1cn	$$⊢1\in ℂ$$
3		df-5	$$⊢5=4+1$$
4	1 2 3	mvrraddi	$$⊢5-1=4$$