set L = TrivOrtLat ;
thus TrivOrtLat is bounded ; :: according to LATTICES:def 20 :: thesis: ( TrivOrtLat is complemented & TrivOrtLat is distributive & TrivOrtLat is well-complemented )
thus TrivOrtLat is complemented :: thesis: ( TrivOrtLat is distributive & TrivOrtLat is well-complemented )
proof end;
thus TrivOrtLat is distributive by STRUCT_0:def 10; :: thesis: TrivOrtLat is well-complemented
let a be Element of TrivOrtLat; :: according to ROBBINS1:def 10 :: thesis: a ` is_a_complement_of a
A1: ( (a `) "\/" a = a "\/" (a `) & (a `) "/\" a = a "/\" (a `) ) ;
( (a `) "\/" a = Top TrivOrtLat & (a `) "/\" a = Bottom TrivOrtLat ) by STRUCT_0:def 10;
hence a ` is_a_complement_of a by A1; :: thesis: verum