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 >. } u. { <. ( le ` ndx ) , .<_ >. , <. ( oc ` ndx ) , ._|_ >. } ) Struct <. 1 , ; 1 1 >.

Proof

Step Hyp Ref Expression
1 1nn
 |-  1 e. NN
2 basendx
 |-  ( Base ` ndx ) = 1
3 1lt9
 |-  1 < 9
4 9nn
 |-  9 e. NN
5 tsetndx
 |-  ( TopSet ` ndx ) = 9
6 1 2 3 4 5 strle2
 |-  { <. ( Base ` ndx ) , B >. , <. ( TopSet ` ndx ) , J >. } Struct <. 1 , 9 >.
7 10nn
 |-  ; 1 0 e. NN
8 plendx
 |-  ( le ` ndx ) = ; 1 0
9 1nn0
 |-  1 e. NN0
10 0nn0
 |-  0 e. NN0
11 0lt1
 |-  0 < 1
12 9 10 1 11 declt
 |-  ; 1 0 < ; 1 1
13 9 1 decnncl
 |-  ; 1 1 e. NN
14 ocndx
 |-  ( oc ` ndx ) = ; 1 1
15 7 8 12 13 14 strle2
 |-  { <. ( le ` ndx ) , .<_ >. , <. ( oc ` ndx ) , ._|_ >. } Struct <. ; 1 0 , ; 1 1 >.
16 9lt10
 |-  9 < ; 1 0
17 6 15 16 strleun
 |-  ( { <. ( Base ` ndx ) , B >. , <. ( TopSet ` ndx ) , J >. } u. { <. ( le ` ndx ) , .<_ >. , <. ( oc ` ndx ) , ._|_ >. } ) Struct <. 1 , ; 1 1 >.