set L = ExNearLattice ;
reconsider x = 0 , y = 1, z = 2 as Element of ExNearLattice by ENUMSET1:def 1;
reconsider xx = x, yy = y, zz = z as Element of {0,1,2} ;
yy ex123"/\" zz =
min (yy,zz)
by ExMeetDef
.=
1
by XXREAL_0:def 9
;
then t1: x "/\" (y "/\" z) =
x "/\" y
by EXNDef
.=
xx ex123"/\" yy
by EXNDef
.=
min (xx,yy)
by ExMeetDef
.=
0
by XXREAL_0:def 9
;
xx ex123"/\" yy =
min (xx,yy)
by ExMeetDef
.=
0
by XXREAL_0:def 9
;
then (x "/\" y) "/\" z =
x "/\" z
by EXNDef
.=
xx ex123"/\" zz
by EXNDef
.=
2
by ExMeetDef
;
hence
not ExNearLattice is meet-associative
by LATTICES:def 7, t1; verum