Every even integer can be expressed as the sum of two odd integers:
This is my try for the statement a=b+c
$\small(\forall a{\in}\Bbb Z)(\forall b{\in}Z)(\forall c{\in}\Bbb Z)\big[{[( \exists x{\in}\Bbb Z)(a=2x)\wedge(\exists y{\in}\Bbb Z)(b=2y+1)\wedge(\exists z{\in}\Bbb Z)(a=2z+1)]\to[a=b+c]}\big]$
Reference is taken through: