let r be non-zero Sequence of REAL ; for y being strictly_decreasing uSurreal-Sequence
for A being Ordinal st A c= dom r & dom r = dom y holds
for x, z being Surreal st r,y,A name_like x & x == z holds
r,y,A name_like z
let y be strictly_decreasing uSurreal-Sequence; for A being Ordinal st A c= dom r & dom r = dom y holds
for x, z being Surreal st r,y,A name_like x & x == z holds
r,y,A name_like z
let A be Ordinal; ( A c= dom r & dom r = dom y implies for x, z being Surreal st r,y,A name_like x & x == z holds
r,y,A name_like z )
assume
( A c= dom r & dom r = dom y )
; for x, z being Surreal st r,y,A name_like x & x == z holds
r,y,A name_like z
let x, z be Surreal; ( r,y,A name_like x & x == z implies r,y,A name_like z )
assume A2:
( r,y,A name_like x & x == z )
; r,y,A name_like z
thus
( A c= dom r & dom r = dom y )
by A2; SURREALC:def 19 for beta being Ordinal st beta in A holds
for Pb being Surreal st Pb = (Partial_Sums (r,y)) . beta holds
( not z == Pb & r . beta = omega-r (z - Pb) & y . beta = omega-y (z - Pb) )
let B be Ordinal; ( B in A implies for Pb being Surreal st Pb = (Partial_Sums (r,y)) . B holds
( not z == Pb & r . B = omega-r (z - Pb) & y . B = omega-y (z - Pb) ) )
assume A3:
B in A
; for Pb being Surreal st Pb = (Partial_Sums (r,y)) . B holds
( not z == Pb & r . B = omega-r (z - Pb) & y . B = omega-y (z - Pb) )
let Pb be Surreal; ( Pb = (Partial_Sums (r,y)) . B implies ( not z == Pb & r . B = omega-r (z - Pb) & y . B = omega-y (z - Pb) ) )
assume A4:
Pb = (Partial_Sums (r,y)) . B
; ( not z == Pb & r . B = omega-r (z - Pb) & y . B = omega-y (z - Pb) )
thus
not z == Pb
by A2, A3, A4, SURREALO:10; ( r . B = omega-r (z - Pb) & y . B = omega-y (z - Pb) )
A5:
x - Pb == z - Pb
by A2, SURREALR:66;
A6:
( not x == Pb & r . B = omega-r (x - Pb) & y . B = omega-y (x - Pb) )
by A2, A3, A4;
then
not x - Pb == 0_No
by SURREALR:45, SURREALR:46;
hence
( r . B = omega-r (z - Pb) & y . B = omega-y (z - Pb) )
by A5, A6, Th70; verum