Changes between Version 12 and Version 13 of Symbolic Expressions

Timestamp:

02/13/10 16:48:25 (16 years ago)

Author:

Stephen Siegel

Comment:

--

Symbolic Expressions

@@ -67 +67 @@
  
   
-In util wee need to export:
+In util we need to export:
 * Rational /* infinite precision rational numbers */
    * static Rational rational(int value);
@@ -93 +93 @@
 The idea is to aggressively put every expression into a canonical form.  It assumes real arithmetic, so addition and multiplication are as in the real numbers.
 
+Additional Interfaces:
+* PrimitiveCExpressionIF
+    * classes implementing this interface
+       * ArrayRead
+       * ArrayWrite
+       * TupleRead
+       * TupleWrite
+       * SymbolicConstant
+       * RelationalCExpression
+       * EvaluatedFunction
+
 Classes:
-
  * CExpression implements SymbolicExpressionIF
  * AndCExpression extends CExpression
     * clauses: set of OrCExpression
  * OrCExpression extends CExpression
-    * clauses: set of SBasicExpression
+    * clauses: set of BasicCExpression
  * BasicCExpression extends CExpression
-    * RelationalCExpression, or
-    * PrimitiveCExpression, where PrimitiveCExpression has boolean type, or
-    * !PrimitiveCExpression
- * RelationalCExpression extends CExpression
-   * e>0, e>=0, e=0, e!=0, where e is a PolynomialCExpression
- * PrimitiveCExpression extends CExpression
-   * X, where X is a symbolic constant
-   * a[e], a is a CExpression of array type, e a CExpression of integer type
-   * r.f, where r is an CExpression of tuple type and f is a nonnegative integer
+    * boolean not(); /* if true insert not here */
+    * PrimitiveCExpressionIF primitiveExpression();
+ * RelationalCExpression extends CExpression implements PrimitiveCExpressionIF
+   * enum RelationKind { GT0, EQ0 };
+   * RelationKind kind();
+   * PolynomialCExpression expression();
  * PolynomialCExpression extends CExpression
     * terms: set of MonomialCExpression
@@ -117 +124 @@
  * RationalCExpression extends CExpression
     * numerator, denominator: PolynomialCExpression
+
+Some facts which show how to put any expression into this canonical form:
+ * x>=y <=> !(y-x>0)
+ * x<y <=> y-x>0
+ * x<=y <=> !(x-y>0)
+
+Big question: how to find command factors in denominator?
+ 
 
 === CExpressionFactory ===