Metamath Proof Explorer


Theorem xrhmph

Description: The extended reals are homeomorphic to the interval [ 0 , 1 ] . (Contributed by Mario Carneiro, 9-Sep-2015)

Ref Expression
Assertion xrhmph II ordTop

Proof

Step Hyp Ref Expression
1 neg1rr 1
2 1re 1
3 neg1lt0 1 < 0
4 0lt1 0 < 1
5 0re 0
6 1 5 2 lttri 1 < 0 0 < 1 1 < 1
7 3 4 6 mp2an 1 < 1
8 eqid TopOpen fld = TopOpen fld
9 eqid x 0 1 x 1 + 1 x -1 = x 0 1 x 1 + 1 x -1
10 8 9 icchmeo 1 1 1 < 1 x 0 1 x 1 + 1 x -1 II Homeo TopOpen fld 𝑡 1 1
11 1 2 7 10 mp3an x 0 1 x 1 + 1 x -1 II Homeo TopOpen fld 𝑡 1 1
12 hmphi x 0 1 x 1 + 1 x -1 II Homeo TopOpen fld 𝑡 1 1 II TopOpen fld 𝑡 1 1
13 11 12 ax-mp II TopOpen fld 𝑡 1 1
14 eqid x 0 1 if x = 1 +∞ x 1 x = x 0 1 if x = 1 +∞ x 1 x
15 eqid y 1 1 if 0 y x 0 1 if x = 1 +∞ x 1 x y x 0 1 if x = 1 +∞ x 1 x y = y 1 1 if 0 y x 0 1 if x = 1 +∞ x 1 x y x 0 1 if x = 1 +∞ x 1 x y
16 14 15 8 xrhmeo y 1 1 if 0 y x 0 1 if x = 1 +∞ x 1 x y x 0 1 if x = 1 +∞ x 1 x y Isom < , < 1 1 * y 1 1 if 0 y x 0 1 if x = 1 +∞ x 1 x y x 0 1 if x = 1 +∞ x 1 x y TopOpen fld 𝑡 1 1 Homeo ordTop
17 16 simpri y 1 1 if 0 y x 0 1 if x = 1 +∞ x 1 x y x 0 1 if x = 1 +∞ x 1 x y TopOpen fld 𝑡 1 1 Homeo ordTop
18 hmphi y 1 1 if 0 y x 0 1 if x = 1 +∞ x 1 x y x 0 1 if x = 1 +∞ x 1 x y TopOpen fld 𝑡 1 1 Homeo ordTop TopOpen fld 𝑡 1 1 ordTop
19 17 18 ax-mp TopOpen fld 𝑡 1 1 ordTop
20 hmphtr II TopOpen fld 𝑡 1 1 TopOpen fld 𝑡 1 1 ordTop II ordTop
21 13 19 20 mp2an II ordTop