From the principle λProlog page:

λProlog is a logic programming language based on an intuitionistic fragment of Church's Simple Theory of Types. Such a strong logical foundation provides λProlog with logically supported notions of

modular programming,

abstract datatypes,

higher-order programming, and

the lambda-tree syntax approach to the treatment of bound variables in syntax.

Implementations of λProlog contain implementations of the simply typed λ-terms as well as (of subsets) of higher-order unification.

The syntax is similar to Prolog, but it extends Prolog's basis of Horn clause logic to higher-order hereditary Harrop formulas. Its higher-order nature allows for quantifying over predicates, and its basis in lambda-tree syntax facilitates construction of terms using lambda abstraction. All λProlog predicates require explicit type signatures.

λProlog was first developed in 1986. It has had a number implementations, and is still under active development.