let AFV be WeakAffVect; for a, b, c, b', c' being Element of st Mid a,b,c & Mid a,b',c' & MDist b,b' holds
c = c'
let a, b, c, b', c' be Element of ; ( Mid a,b,c & Mid a,b',c' & MDist b,b' implies c = c' )
assume that
A1:
Mid a,b,c
and
A2:
Mid a,b',c'
and
A3:
MDist b,b'
; c = c'
Mid a,b',c
by A1, A3, Th28;
hence
c = c'
by A2, Th27; verum