

  To install ft from a directory containing the files


ft.h   		formula.c	print.c		sift.c
		main.c		prop.c		skeleton.c
		makefile	prove.c		stack.c
		pprove.c	set.c		unify.c


just incant "make". There is some Unix-specific stuff in main.c: the
program will work under 4.2BSD and 4.3BSD. (4.3BSD will complain harm-
lessly: see the comment in main.c.) In addition to the above files, the
present directory contains ftmanual and a subdirectory examples/ containing
the files benchmarks.pred and benchmarks.prop.
  
  ft uses a somewhat involved algorithm to attempt to prove formulas
in intuitionistic predicate logic, and to decide whether a formula in
intuitionistic propositional logic is valid. For a full presentation
of the algorithm, see "An Intuitionistic Predicate Logic Theorem
Prover" by Sahlin, Franzen, and Haridi, forthcoming in the Journal of Logic and
Computation. The manual included here is quite sufficient to allow
anybody to experiment with the system. The present implementation does
not include any treatment of identity: a Prolog implementation
incorporating identity is also available or will be available shortly.

  Please mail bug reports to torkel@sics.se or to Torkel Franzen, SICS,
Box 1263, S-164 28 Kista, Sweden.

  You are free to use or modify this code in any way you wish, as long
as any further distribution of the code includes i) a statement that
it originates at SICS, and ii) a description of the modifications that have
been made.


