let UN be Universe; :: thesis: ( {{} } in UN & [{{} },{{} }] in UN & [:{{} },{{} }:] in UN & op2 in UN & op1 in UN )
set D = {{} };
thus A1:
{{} } in UN
by CLASSES2:62, CLASSES2:63; :: thesis: ( [{{} },{{} }] in UN & [:{{} },{{} }:] in UN & op2 in UN & op1 in UN )
hence
[{{} },{{} }] in UN
by CLASSES2:64; :: thesis: ( [:{{} },{{} }:] in UN & op2 in UN & op1 in UN )
thus A2:
[:{{} },{{} }:] in UN
by A1, CLASSES2:67; :: thesis: ( op2 in UN & op1 in UN )
A3:
Funcs {{} },{{} } in UN
by A1, CLASSES2:67;
A4:
Funcs [:{{} },{{} }:],{{} } in UN
by A1, A2, CLASSES2:67;
op2 in Funcs [:{{} },{{} }:],{{} }
by CARD_1:87, FUNCT_2:11;
hence
op2 in UN
by A4, Th4; :: thesis: op1 in UN
op1 in Funcs {{} },{{} }
by CARD_1:87, FUNCT_2:11;
hence
op1 in UN
by A3, Th4; :: thesis: verum