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 BasendxBTopSetndxJndx˙ocndx˙Struct111

Proof

Step Hyp Ref Expression
1 1nn 1
2 basendx Basendx=1
3 1lt9 1<9
4 9nn 9
5 tsetndx TopSetndx=9
6 1 2 3 4 5 strle2 BasendxBTopSetndxJStruct19
7 10nn 10
8 plendx ndx=10
9 1nn0 10
10 0nn0 00
11 0lt1 0<1
12 9 10 1 11 declt 10<11
13 9 1 decnncl 11
14 ocndx ocndx=11
15 7 8 12 13 14 strle2 ndx˙ocndx˙Struct1011
16 9lt10 9<10
17 6 15 16 strleun BasendxBTopSetndxJndx˙ocndx˙Struct111