Curry-Howard Exercise

ModusTollens.cs

// (A => B and not B) => not A
Not<A> ModusTollens<A, B>(
	Func<A, B> A_implies_B,
	Not<B> not_B)
{
	Absurd A_to_Absurd(A a)
	{
	    return not_B.Apply(A_implies_B(a));
	}
	return new Not<A>(A_to_Absurd);
}

Syllogism.cs

// (A => B and B  => C) => A => C
Func<A, C> Syllogism<A, B, C>(
	Func<A, B> A_implies_B,
	Func<B, C> B_implies_C)
{	
    C Composed(A a)
    {
        return B_implies_C(A_implies_B(a));
    }
    return Composed;
}