Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Replacement
Theorems requiring subset and intersection existence
difexg
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difexi
Metamath Proof Explorer
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Theorem
difexg
Description:
Existence of a difference.
(Contributed by
NM
, 26-May-1998)
Ref
Expression
Assertion
difexg
⊢
A
∈
V
→
A
∖
B
∈
V
Proof
Step
Hyp
Ref
Expression
1
difss
⊢
A
∖
B
⊆
A
2
ssexg
⊢
A
∖
B
⊆
A
∧
A
∈
V
→
A
∖
B
∈
V
3
1
2
mpan
⊢
A
∈
V
→
A
∖
B
∈
V