let a, b be non empty Nat; :: thesis: ( a,b are_relative_prime implies support (pfexp a) misses support (pfexp b) )
assume
a,b are_relative_prime
; :: thesis: support (pfexp a) misses support (pfexp b)
then A1:
a gcd b = 1
by INT_2:def 4;
set f = pfexp a;
set g = pfexp b;
assume
support (pfexp a) meets support (pfexp b)
; :: thesis: contradiction
then consider x being set such that
A2:
x in support (pfexp a)
and
A3:
x in support (pfexp b)
by XBOOLE_0:3;
reconsider x = x as Prime by A2, Th34;
A5:
(pfexp a) . x <> 0
by A2, POLYNOM1:def 7;
A6:
(pfexp a) . x = x |-count a
by Def8;
A7:
x <> 1
by INT_2:def 5;
then A8:
x |^ (x |-count a) divides a
by Def7;
x divides x |^ (x |-count a)
by A5, A6, Th3;
then A9:
x divides a
by A8, NAT_D:4;
A10:
(pfexp b) . x <> 0
by A3, POLYNOM1:def 7;
A11:
(pfexp b) . x = x |-count b
by Def8;
A12:
x |^ (x |-count b) divides b
by A7, Def7;
x divides x |^ (x |-count b)
by A10, A11, Th3;
then
x divides b
by A12, NAT_D:4;
then
x divides 1
by A1, A9, NAT_D:def 5;
hence
contradiction
by A7, WSIERP_1:20; :: thesis: verum