Metamath Proof Explorer


Theorem iineq2dv

Description: Equality deduction for indexed intersection. (Contributed by NM, 3-Aug-2004)

Ref Expression
Hypothesis iuneq2dv.1 φxAB=C
Assertion iineq2dv φxAB=xAC

Proof

Step Hyp Ref Expression
1 iuneq2dv.1 φxAB=C
2 nfv xφ
3 2 1 iineq2d φxAB=xAC