Summary

Summary

Other BDD pictures:

• 
  BDD graph for the Boolean formula x1 * x2 + x3 * x4 + x5 * x6 + x7 * x8 using a good variable ordering
• 
  BDD graph for the Boolean formula x1 * x2 + x3 * x4 + x5 * x6 + x7 * x8 using a bad variable ordering
• 
  Visualization of the BDD for the Boolean formula x1 * x2 + x3 * x4 + ... + x19 * x20 using a bad variable ordering

The following is the RML (Relational Manipulation Language) code that I fed to CrocoPat to produce the GraphViz dot files:

// RML program to generate a BDD graph for the formula
// !x1 & !x2 & !x3  |  x1 & x2  |  x2 & x3,
// using the variable ordering <x1, x2, x3>.
// "crocopat -e BDD_simple.rml" generates a file in dot format.
// "dot -Tsvg BDD_simple.dot -o BDD_Variable_Ordering_Bad.svg"
// generates a file in SVG format from the file in dot format.

// There are two ('Boolean') values for the variables x1, x2, x3.
DOM("0");
DOM("1");

// F is the name of the Boolean formula.
F(x1,x2,x3) :=  (x1="0" & x2="0" & x3="0") 
              | (x1="1" & x2="1")
              | (x2="1" & x3="1");

// Prints the BDD as graph in GraphViz dot format.
PRINT GRAPH( F(x1,x2,x3) ) TO "BDD_simple.dot";

Licensing

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