let n be Nat; ( not n divides 36 or n = 1 or n = 2 or n = 3 or n = 4 or n = 6 or n = 9 or n = 12 or n = 18 or n = 36 )
assume
n divides 36
; ( n = 1 or n = 2 or n = 3 or n = 4 or n = 6 or n = 9 or n = 12 or n = 18 or n = 36 )
then
n divides 6 * 6
;
then consider a, b being Nat such that
A1:
( a divides 6 & b divides 6 )
and
A2:
n = a * b
by Lem1;
( ( a = 1 or a = 2 or a = 3 or a = 6 ) & ( b = 1 or b = 2 or b = 3 or b = 6 ) )
by A1, Th10;
hence
( n = 1 or n = 2 or n = 3 or n = 4 or n = 6 or n = 9 or n = 12 or n = 18 or n = 36 )
by A2; verum