Theorem itgeq1

Description: Equality theorem for an integral. (Contributed by Mario Carneiro, 28-Jun-2014)

	Ref	Expression
Assertion	itgeq1	$$⊢A=B\to {\int }_{A}Cdx={\int }_{B}Cdx$$

Proof

Step	Hyp	Ref	Expression
1		nfcv	$$⊢\underset{\_}{Ⅎ}xA$$
2		nfcv	$$⊢\underset{\_}{Ⅎ}xB$$
3	1 2	itgeq1f	$$⊢A=B\to {\int }_{A}Cdx={\int }_{B}Cdx$$