Metamath Proof Explorer


Theorem ipostr

Description: The structure of df-ipo is a structure defining indices up to 11. (Contributed by Mario Carneiro, 25-Oct-2015)

Ref Expression
Assertion ipostr Base ndx B TopSet ndx J ndx ˙ oc ndx ˙ Struct 1 11

Proof

Step Hyp Ref Expression
1 1nn 1
2 basendx Base ndx = 1
3 1lt9 1 < 9
4 9nn 9
5 tsetndx TopSet ndx = 9
6 1 2 3 4 5 strle2 Base ndx B TopSet ndx J Struct 1 9
7 10nn 10
8 plendx ndx = 10
9 1nn0 1 0
10 0nn0 0 0
11 0lt1 0 < 1
12 9 10 1 11 declt 10 < 11
13 9 1 decnncl 11
14 ocndx oc ndx = 11
15 7 8 12 13 14 strle2 ndx ˙ oc ndx ˙ Struct 10 11
16 9lt10 9 < 10
17 6 15 16 strleun Base ndx B TopSet ndx J ndx ˙ oc ndx ˙ Struct 1 11