1903-1995

Church
was an
American
mathematician
and
logician
who made major contributions to mathematical logic and the foundations of
theoretical
computer science.
He is best known for the
lambda calculus,
Church's thesis
and the
Church-Rosser theorem.
In
mathematical logic and
computer science,
lambda calculus,
also written as λ-calculus,
is a
formal system designed to investigate
function definition, function application and
recursion..
In
computability theory the
Church–Turing thesis
(also known as Church's
thesis, Church's
conjecture and
Turing's thesis) is a combined
hypothesis about the nature of
effectively calculable (computable) functions by
recursion (Church's Thesis), by mechanical device
equivalent to a
Turing machine (Turing's Thesis) or by use of Church's
λ-calculus:
The Church–Rosser theorem
states that if there are two distinct reductions starting from the
same
lambda calculus term, then there exists a term that is
reachable via a (possibly empty) sequence of reductions from both
reducts. |