Trilogy
A {strongly typed} {logic programming} language
with numerical {constraint}-solving over the {natural
numbers}, developed by Paul Voda
at {UBC} in 1988. Trilogy is syntactically a blend of
{Prolog}, {Lisp}, and {Pascal}. It contains three types of
{clauses}: {predicates} ({backtracking} but no assignable
variables), procedures (if-then-else but no backtracking;
assignable variables), and {subroutines} (like procedures, but
with input and {system calls}; callable only from top level or
from other subroutines).
Development of Trilogy I stopped in 1991. Trilogy II,
developed by Paul Voda 1988-92, was a {declarative} general
purpose programming language, used for teaching and to write
{CL}.
{(http://www.fmph.uniba.sk/~voda)}.
["The Constraint Language Trilogy: Semantics and
Computations", P. Voda, Complete Logic Systems, 741 Blueridge
Ave, North Vancouver BC, V7R 2J5].
(2000-04-08)