.\" SCCSID: @(#)fp.1	8.1	9/11/90.\" Last modified by MJT on 26-Aug-85  23.\"  Repaired beginning matter to work right in whatis database.\"  Deleted defined string s, which provided variable section.\"   number for lisp and liszt -- used plain old IR instead.TH fp 1 VAX "" Unsupported.SH Namefp \- Functional Programming language compiler/interpreter.SH Syntax.B fp.SH DescriptionThe.PN fpinterpreter/compiler implements the applicative language proposedby John Backus.  It is written in.SM "FRANZ LISP" ..PPIn a  functional programming languageintent is expressedin  a mathematical style devoid of assignment statementsand variables.Functions compute by value only; there are no side-effectssince  the result of a computation depends solely on the inputs..PPThe.PN fpprograms consist of.I functional expressions \-primitive and user-defined .PN fpfunctionscombined by .I functional forms.These forms take functional argumentsand return functional results.For example, the compositionoperator .I '@'takes two functional arguments and returns a functionwhich represents their composition..PPThere exists a single operation in .PN fp\&\-.I application.This operation causes the system to evaluate the indicated function usingthe single argument as input(all functions are monadic)..SS Getting Started.PN fpinvokes the system.  .PN fpcompiles functions into.IR lisp (1)source code;.IR lisp (1)interprets this code(the user may compile this code using the.IR liszt (1)compiler to gain a factor of 10 in performance).Ctrl Dexits back to the shell..I Breakterminates any computation in progress  and resets any open file units..I )helpprovides a short summary of all user commands..SH RestrictionsIf a non-terminating function is applied as the result of loading a file,then control is returned to the user immediately, everythingafter that position in the file is ignored..PP.PN fp incorrectly marks the location of a syntax error onlarge, multi-line function definitions or applications.(Turing award lecture by John Backus)..SH Files.DT/usr/ucb/lisp	the FRANZ LISP interpreter.br/usr/ucb/liszt	the liszt compiler.br/usr/doc/fp	the User's Guide.SH See Alsolisp(1),liszt (1)..br"The FRANZ LISP Manual" in the\fISupplementary Documents, Volume 2: Programmer\fP