Lower Bound Cost Estimation

• The (lower bound) computational cost ( ) of a clause:
• .

• .

• where:
  • is the input argument size for the head of the clause.
  • denotes a lower bound on the cost of the body literal .
  • are (lower bounds on) the input argument sizes for the body literals respectively.
  • is a lower bound on the cost of head unification and tests.
  • is the rightmost body literal that is guaranteed not to fail.

• A lower bound on the cost of a procedure for an input of size is given by:

  .