Metamath Proof Explorer


Theorem xrge0iifmhm

Description: The defined function from the closed unit interval to the extended nonnegative reals is a monoid homomorphism. (Contributed by Thierry Arnoux, 21-Jun-2017)

Ref Expression
Hypotheses xrge0iifhmeo.1 F = x 0 1 if x = 0 +∞ log x
xrge0iifhmeo.k J = ordTop 𝑡 0 +∞
Assertion xrge0iifmhm F mulGrp fld 𝑠 0 1 MndHom 𝑠 * 𝑠 0 +∞

Proof

Step Hyp Ref Expression
1 xrge0iifhmeo.1 F = x 0 1 if x = 0 +∞ log x
2 xrge0iifhmeo.k J = ordTop 𝑡 0 +∞
3 eqid mulGrp fld 𝑠 0 1 = mulGrp fld 𝑠 0 1
4 3 iistmd mulGrp fld 𝑠 0 1 TopMnd
5 tmdmnd mulGrp fld 𝑠 0 1 TopMnd mulGrp fld 𝑠 0 1 Mnd
6 4 5 ax-mp mulGrp fld 𝑠 0 1 Mnd
7 xrge0cmn 𝑠 * 𝑠 0 +∞ CMnd
8 cmnmnd 𝑠 * 𝑠 0 +∞ CMnd 𝑠 * 𝑠 0 +∞ Mnd
9 7 8 ax-mp 𝑠 * 𝑠 0 +∞ Mnd
10 6 9 pm3.2i mulGrp fld 𝑠 0 1 Mnd 𝑠 * 𝑠 0 +∞ Mnd
11 1 xrge0iifcnv F : 0 1 1-1 onto 0 +∞ F -1 = y 0 +∞ if y = +∞ 0 e y
12 11 simpli F : 0 1 1-1 onto 0 +∞
13 f1of F : 0 1 1-1 onto 0 +∞ F : 0 1 0 +∞
14 12 13 ax-mp F : 0 1 0 +∞
15 1 2 xrge0iifhom y 0 1 z 0 1 F y z = F y + 𝑒 F z
16 15 rgen2 y 0 1 z 0 1 F y z = F y + 𝑒 F z
17 1 2 xrge0iif1 F 1 = 0
18 14 16 17 3pm3.2i F : 0 1 0 +∞ y 0 1 z 0 1 F y z = F y + 𝑒 F z F 1 = 0
19 unitsscn 0 1
20 eqid mulGrp fld = mulGrp fld
21 cnfldbas = Base fld
22 20 21 mgpbas = Base mulGrp fld
23 3 22 ressbas2 0 1 0 1 = Base mulGrp fld 𝑠 0 1
24 19 23 ax-mp 0 1 = Base mulGrp fld 𝑠 0 1
25 xrge0base 0 +∞ = Base 𝑠 * 𝑠 0 +∞
26 cnfldex fld V
27 ovex 0 1 V
28 eqid fld 𝑠 0 1 = fld 𝑠 0 1
29 28 20 mgpress fld V 0 1 V mulGrp fld 𝑠 0 1 = mulGrp fld 𝑠 0 1
30 26 27 29 mp2an mulGrp fld 𝑠 0 1 = mulGrp fld 𝑠 0 1
31 cnfldmul × = fld
32 28 31 ressmulr 0 1 V × = fld 𝑠 0 1
33 27 32 ax-mp × = fld 𝑠 0 1
34 30 33 mgpplusg × = + mulGrp fld 𝑠 0 1
35 xrge0plusg + 𝑒 = + 𝑠 * 𝑠 0 +∞
36 cnring fld Ring
37 1elunit 1 0 1
38 cnfld1 1 = 1 fld
39 3 21 38 ringidss fld Ring 0 1 1 0 1 1 = 0 mulGrp fld 𝑠 0 1
40 36 19 37 39 mp3an 1 = 0 mulGrp fld 𝑠 0 1
41 xrge00 0 = 0 𝑠 * 𝑠 0 +∞
42 24 25 34 35 40 41 ismhm F mulGrp fld 𝑠 0 1 MndHom 𝑠 * 𝑠 0 +∞ mulGrp fld 𝑠 0 1 Mnd 𝑠 * 𝑠 0 +∞ Mnd F : 0 1 0 +∞ y 0 1 z 0 1 F y z = F y + 𝑒 F z F 1 = 0
43 10 18 42 mpbir2an F mulGrp fld 𝑠 0 1 MndHom 𝑠 * 𝑠 0 +∞