Database
BASIC ORDER THEORY
Lattices
Lattices
latmle1
Next ⟩
latmle2
Metamath Proof Explorer
Ascii
Unicode
Theorem
latmle1
Description:
A meet is less than or equal to its first argument.
(Contributed by
NM
, 21-Oct-2011)
Ref
Expression
Hypotheses
latmle.b
⊢
B
=
Base
K
latmle.l
⊢
≤
˙
=
≤
K
latmle.m
⊢
∧
˙
=
meet
⁡
K
Assertion
latmle1
⊢
K
∈
Lat
∧
X
∈
B
∧
Y
∈
B
→
X
∧
˙
Y
≤
˙
X
Proof
Step
Hyp
Ref
Expression
1
latmle.b
⊢
B
=
Base
K
2
latmle.l
⊢
≤
˙
=
≤
K
3
latmle.m
⊢
∧
˙
=
meet
⁡
K
4
simp1
⊢
K
∈
Lat
∧
X
∈
B
∧
Y
∈
B
→
K
∈
Lat
5
simp2
⊢
K
∈
Lat
∧
X
∈
B
∧
Y
∈
B
→
X
∈
B
6
simp3
⊢
K
∈
Lat
∧
X
∈
B
∧
Y
∈
B
→
Y
∈
B
7
eqid
⊢
join
⁡
K
=
join
⁡
K
8
1
7
3
4
5
6
latcl2
⊢
K
∈
Lat
∧
X
∈
B
∧
Y
∈
B
→
X
Y
∈
dom
⁡
join
⁡
K
∧
X
Y
∈
dom
⁡
∧
˙
9
8
simprd
⊢
K
∈
Lat
∧
X
∈
B
∧
Y
∈
B
→
X
Y
∈
dom
⁡
∧
˙
10
1
2
3
4
5
6
9
lemeet1
⊢
K
∈
Lat
∧
X
∈
B
∧
Y
∈
B
→
X
∧
˙
Y
≤
˙
X