Solving a Set of Equations by Search

• Try to find an equation where all variables are known except one.

  
  (= F (* M A))
  

• Solve the equation for that variable.

  
  (= A (/ F M))
  

• Substitute the known values into the right-hand side of the solved equation (Lisp function sublis).

  
  (= A (/ 8 2))
  

• Evaluate the resulting expression (Lisp function eval) to give the value of the new variable. Add that variable to the binding list.

  
  (= A 4)
  

• Keep trying until you get the value of the variable you want (or quit if you stop making any progress).