let a, b be positive heavy Real; ( log (a,b) > log (b,a) & log (b,a) >= 1 implies a > b )
A1:
( a > 1 & b > 1 )
by TA1;
assume A2:
log (a,b) > log (b,a)
; ( not log (b,a) >= 1 or a > b )
assume
log (b,a) >= 1
; a > b
then B2:
log (b,a) >= log (b,b)
by A1, POWER:52;
B4:
a <> b
by A2;
a >= b
by A1, B2, POWER:57;
hence
a > b
by B4, XXREAL_0:1; verum