DIRECTORY IO USING [STREAM], Rope USING [ROPE];Boole: CEDAR DEFINITIONS = BEGINExpression: TYPE = REF;Variable: TYPE = REF; true: READONLY Expression;false: READONLY Expression;Not: PROC [expr: Expression] RETURNS [result: Expression];And: PROC [expr1, expr2, expr3, expr4, expr5: Expression _ true] RETURNS [result: Expression];Or: PROC [expr1, expr2, expr3, expr4, expr5: Expression _ false] RETURNS [result: Expression];Xor: PROC [expr1, expr2, expr3, expr4, expr5: Expression _ false] RETURNS [result: Expression];Nand: PROC [expr1, expr2, expr3, expr4, expr5: Expression _ true] RETURNS [result: Expression];Nor: PROC [expr1, expr2, expr3, expr4, expr5: Expression _ false] RETURNS [result: Expression];AndList: PROC [exprs: LIST OF Expression] RETURNS [result: Expression];OrList: PROC [exprs: LIST OF Expression] RETURNS [result: Expression];XorList: PROC [exprs: LIST OF Expression] RETURNS [result: Expression];NandList: PROC [exprs: LIST OF Expression] RETURNS [result: Expression];NorList: PROC [exprs: LIST OF Expression] RETURNS [result: Expression];If: PROC [cond, then, else: Expression] RETURNS [result: Expression];EqualVar: PROC [var1, var2: Variable] RETURNS [BOOL];Equal: PROC [expr1, expr2: Expression] RETURNS [BOOL];Eval: PROC [var: Variable, expr: Expression] RETURNS [whenTrue, whenFalse: Expression];FullEval: PROC [expr: Expression, evalVar: EvalVar] RETURNS [Expression];EvalVar: TYPE = PROC [Variable] RETURNS [Expression];FindVar: PROC [expr: Expression] RETURNS [var: Variable];EnumerateVars: PROC [expr: Expression, enumVar: EnumVar];EnumVar: TYPE = PROC [Variable];HasVar: PROC [expr: Expression, var: Variable] RETURNS [found: BOOL _ FALSE];PutExpr: PROC [out: IO.STREAM, expr: Expression, deep: INT _ LAST [INT], putRefAny: PROC [IO.STREAM, Variable] _ NIL];GetExpr: PROC [in: IO.STREAM, getRefAny: PROC [IO.STREAM] RETURNS [Variable] _ NIL] RETURNS [expr: Expression];ToRope: PROC [expr: Expression, deep: INT _ 5] RETURNS [Rope.ROPE];FromRope: PROC [rope: Rope.ROPE] RETURNS [Expression];Case: PRIVATE PROC [whenTrue, whenFalse: Expression] RETURNS [case: ATOM];END.  ┤  Boole.mesa	Copyright ╙ 1985, 1986, 1987 by Xerox Corporation.  All rights reversed.Created by Bertrand Serlet July 31, 1985 3:03:17 pm PDTBertrand Serlet April 2, 1987 9:34:37 pm PSTBarth, August 26, 1986 9:58:59 am PDTTheoryThis interface defines the basic functions for manipulating Boolean expressions.  Expressions may be:constants among {true, false};variables: any REF.  Variables are tested for equality using the REF Equal predicate, apart from ROPEs which compares using Rope.Equal, and REF INT which compares the INTs.expressions created by operators such as Not, And, Or, If, etc ... .Types and ConstantsOperators returning ExpressionsUseful operator computing: Or[And[cond, then], And[Not[cond], else]].Other operationsNIL means unknown when returned from FullEval or EvalVar.NIL if no var found or insignificant.Variables which are ROPE or REF INT are handled without calling putRefAny.Variables which are ROPE or REF INT are handled without calling getRefAnyShort cut for PutExprShort cut for GetExprPrivate operations that depend on the representationcase belongs to {$Case11, $Case00, $Case10, $Case01, $Case1X, $Case0X, $CaseX1, $CaseX0, $CaseXX, $CaseXY}Э╩х  Ш Ц"Cedar" styleЪЬЩJЪЬHЩHJЩ7JЩ,IcodeЩ%ЧJШ Ъ╧k	ЬШ
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