Theorem 2fveq3

Description: Equality theorem for nested function values. (Contributed by AV, 14-Aug-2022)

	Ref	Expression
Assertion	2fveq3	$$⊢A=B\to F\left(G\left(A\right)\right)=F\left(G\left(B\right)\right)$$

Proof

Step	Hyp	Ref	Expression
1		fveq2	$$⊢A=B\to G\left(A\right)=G\left(B\right)$$
2	1	fveq2d	$$⊢A=B\to F\left(G\left(A\right)\right)=F\left(G\left(B\right)\right)$$