Description: A homotopy from a path to itself. (Contributed by Jeff Madsen, 2-Sep-2009) (Revised by Mario Carneiro, 23-Feb-2015)
Ref | Expression | ||
---|---|---|---|
Hypotheses | phtpyid.1 | |
|
phtpyid.3 | |
||
Assertion | phtpyid | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | phtpyid.1 | |
|
2 | phtpyid.3 | |
|
3 | iitopon | |
|
4 | 3 | a1i | |
5 | 1 4 2 | htpyid | |
6 | 0elunit | |
|
7 | fveq2 | |
|
8 | eqidd | |
|
9 | fvex | |
|
10 | 7 8 1 9 | ovmpo | |
11 | 6 10 | mpan | |
12 | 11 | adantl | |
13 | 1elunit | |
|
14 | fveq2 | |
|
15 | eqidd | |
|
16 | fvex | |
|
17 | 14 15 1 16 | ovmpo | |
18 | 13 17 | mpan | |
19 | 18 | adantl | |
20 | 2 2 5 12 19 | isphtpyd | |