(
SECD machine) The first
abstract machine for reducing
lambda-calculus expressions, invented by P. J. Landin. The
machine has four
registers holding pointers to {linked
lists} operated as push-down
stacks which hold the
information required for the evaluation of an expression. The
registers point to (1) Stack which holds the arguments of
partially evaluated expressions and results of completely
evaluated ones, (2) Environment where the current expression
being evaluated is stored, (3) Control which holds the
machine
instructions that manipulate the contents of the four
registers that represent the expression being evaluated, (4)
Dump on which the state of the
machine is temporarily saved
during the evaluation of expressions. See also
Lispkit.