A5:
for n being Nat
for x, y1, y2 being Element of REAL st S1[n,x,y1] & S1[n,x,y2] holds
y1 = y2
;
reconsider r1 = r as Element of REAL by XREAL_0:def 1;
let g1, g2 be Real_Sequence; ( g1 . 0 = r & ( for n being Nat holds g1 . (n + 1) = 1 / (frac (g1 . n)) ) & g2 . 0 = r & ( for n being Nat holds g2 . (n + 1) = 1 / (frac (g2 . n)) ) implies g1 = g2 )
assume that
A6:
g1 . 0 = r
and
A7:
for n being Nat holds g1 . (n + 1) = 1 / (frac (g1 . n))
and
A8:
g2 . 0 = r
and
A9:
for n being Nat holds g2 . (n + 1) = 1 / (frac (g2 . n))
; g1 = g2
A10:
for n being Nat holds S1[n,g1 . n,g1 . (n + 1)]
by A7;
A11:
for n being Nat holds S1[n,g2 . n,g2 . (n + 1)]
by A9;
A12:
g2 . 0 = r1
by A8;
A13:
g1 . 0 = r1
by A6;
thus
g1 = g2
from NAT_1:sch 14(A13, A10, A12, A11, A5); verum