let M be non empty locally_euclidean with_boundary TopSpace; for p being Point of M
for pM being Point of (M | (Fr M)) st p = pM holds
for U being a_neighborhood of p
for n being Nat
for h being Function of (M | U),(Tdisk ((0. (TOP-REAL n)),1)) st h is being_homeomorphism & h . p in Sphere ((0. (TOP-REAL n)),1) holds
ex n1 being Nat ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic )
let p be Point of M; for pM being Point of (M | (Fr M)) st p = pM holds
for U being a_neighborhood of p
for n being Nat
for h being Function of (M | U),(Tdisk ((0. (TOP-REAL n)),1)) st h is being_homeomorphism & h . p in Sphere ((0. (TOP-REAL n)),1) holds
ex n1 being Nat ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic )
let pM be Point of (M | (Fr M)); ( p = pM implies for U being a_neighborhood of p
for n being Nat
for h being Function of (M | U),(Tdisk ((0. (TOP-REAL n)),1)) st h is being_homeomorphism & h . p in Sphere ((0. (TOP-REAL n)),1) holds
ex n1 being Nat ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic ) )
assume A1:
p = pM
; for U being a_neighborhood of p
for n being Nat
for h being Function of (M | U),(Tdisk ((0. (TOP-REAL n)),1)) st h is being_homeomorphism & h . p in Sphere ((0. (TOP-REAL n)),1) holds
ex n1 being Nat ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic )
let U be a_neighborhood of p; for n being Nat
for h being Function of (M | U),(Tdisk ((0. (TOP-REAL n)),1)) st h is being_homeomorphism & h . p in Sphere ((0. (TOP-REAL n)),1) holds
ex n1 being Nat ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic )
let n be Nat; for h being Function of (M | U),(Tdisk ((0. (TOP-REAL n)),1)) st h is being_homeomorphism & h . p in Sphere ((0. (TOP-REAL n)),1) holds
ex n1 being Nat ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic )
let h be Function of (M | U),(Tdisk ((0. (TOP-REAL n)),1)); ( h is being_homeomorphism & h . p in Sphere ((0. (TOP-REAL n)),1) implies ex n1 being Nat ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic ) )
assume that
A2:
h is being_homeomorphism
and
A3:
h . p in Sphere ((0. (TOP-REAL n)),1)
; ex n1 being Nat ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic )
set TR = TOP-REAL n;
n > 0
then reconsider n1 = n - 1 as Element of NAT by NAT_1:20;
take
n1
; ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic )
M | U, Tdisk ((0. (TOP-REAL (n1 + 1))),1) are_homeomorphic
by A2, T_0TOPSP:def 1;
then
ex U being a_neighborhood of pM st (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic
by Th7, A1;
hence
ex U being a_neighborhood of pM st
( n1 + 1 = n & (M | (Fr M)) | U, Tball ((0. (TOP-REAL n1)),1) are_homeomorphic )
; verum