set ZS = Rat-Module ;
let s, t be Element of Rat-Module; ( s <> t implies not {s,t} is linearly-independent )
assume AS:
s <> t
; not {s,t} is linearly-independent
assume P1:
{s,t} is linearly-independent
; contradiction
consider m, n being Integer such that
P2:
( n > 0 & s = m / n )
by RAT_1:1;
consider p, q being Integer such that
P3:
( q > 0 & t = p / q )
by RAT_1:1;
reconsider b = n * p as Element of INT.Ring by INT_1:def 2;
reconsider a = q * m as Element of INT.Ring by INT_1:def 2;
P4:
p <> 0. INT.Ring
by AS, P1, P3, ZMODUL02:62;
b * s =
(n * p) * (m / n)
by LMTFRat2, P2
.=
p * m
by P2, XCMPLX_1:90
.=
(q * m) * (p / q)
by P3, XCMPLX_1:90
.=
a * t
by LMTFRat2, P3
;
hence
contradiction
by AS, P1, P2, P4, ZMODUL02:62; verum