Library Coq.Numbers.Integer.Abstract.ZParity
Require
Import
Bool
ZMulOrder
NZParity
.
Some more properties of
even
and
odd
.
Module
Type
ZParityProp
(
Import
Z
:
ZAxiomsSig´
)
(
Import
ZP
:
ZMulOrderProp
Z
).
Include
NZParityProp
Z
Z
ZP
.
Lemma
odd_pred
:
forall
n
,
odd
(
P
n
)
=
even
n
.
Lemma
even_pred
:
forall
n
,
even
(
P
n
)
=
odd
n
.
Lemma
even_opp
:
forall
n
,
even
(
-
n
)
=
even
n
.
Lemma
odd_opp
:
forall
n
,
odd
(
-
n
)
=
odd
n
.
Lemma
even_sub
:
forall
n
m
,
even
(
n
-
m
)
=
Bool.eqb
(
even
n
) (
even
m
).
Lemma
odd_sub
:
forall
n
m
,
odd
(
n
-
m
)
=
xorb
(
odd
n
) (
odd
m
).
End
ZParityProp
.