Database
REAL AND COMPLEX NUMBERS
Order sets
Half-open integer ranges
elfzoelz
Next ⟩
fzoval
Metamath Proof Explorer
Ascii
Unicode
Theorem
elfzoelz
Description:
Reverse closure for half-open integer sets.
(Contributed by
Stefan O'Rear
, 14-Aug-2015)
Ref
Expression
Assertion
elfzoelz
⊢
A
∈
B
..^
C
→
A
∈
ℤ
Proof
Step
Hyp
Ref
Expression
1
elfzoel1
⊢
A
∈
B
..^
C
→
B
∈
ℤ
2
elfzoel2
⊢
A
∈
B
..^
C
→
C
∈
ℤ
3
fzof
⊢
..^
:
ℤ
×
ℤ
⟶
𝒫
ℤ
4
3
fovcl
⊢
B
∈
ℤ
∧
C
∈
ℤ
→
B
..^
C
∈
𝒫
ℤ
5
1
2
4
syl2anc
⊢
A
∈
B
..^
C
→
B
..^
C
∈
𝒫
ℤ
6
5
elpwid
⊢
A
∈
B
..^
C
→
B
..^
C
⊆
ℤ
7
id
⊢
A
∈
B
..^
C
→
A
∈
B
..^
C
8
6
7
sseldd
⊢
A
∈
B
..^
C
→
A
∈
ℤ