Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
The difference, union, and intersection of two classes
The intersection of two classes
ineq1i
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ineq2i
Metamath Proof Explorer
Ascii
Unicode
Theorem
ineq1i
Description:
Equality inference for intersection of two classes.
(Contributed by
NM
, 26-Dec-1993)
Ref
Expression
Hypothesis
ineq1i.1
⊢
A
=
B
Assertion
ineq1i
⊢
A
∩
C
=
B
∩
C
Proof
Step
Hyp
Ref
Expression
1
ineq1i.1
⊢
A
=
B
2
ineq1
⊢
A
=
B
→
A
∩
C
=
B
∩
C
3
1
2
ax-mp
⊢
A
∩
C
=
B
∩
C