Let
An initial -algebra is an initial object in the [[Algebra (Category Theory)|categories of -algebras]].
An initial algebra is the smallest possible object that satisfies the constraints.
An arrow into an initial algebra is called a catamorphism.
Formal definition
An algebra in category theory is a set X, and a function f : F X → X
Initual if it is an initial objecect in the category of algebras
and
Induction ⇒ Initiality