Table/Lambda Calculus abstractions

Admissible data types	Symbolic representation	Description
Variable ($\alpha$ conversion)	x	A character or string representing a parameter or mathematical/logical value.
Substitution ($\beta$ reduction)	(λx.M)(value to be bound to x)	This expression specifies how function is defined by replacing values of bound variable x in the lambda (λ) expression M.
Composition ($\eta$ reduction)	(M N)	Specifying the sequential composition of multiple lambda expressions such as M and N.