31. Additionally, larger problems require more processing, as the operation of counting free variables in unsatisfied clauses dominates the run-time. 32. The problem is that the free variable " x " of " t " became bound during the substitution. 33. As you have observed, C is a free variable . talk ) 10 : 57, 17 January 2012 ( UTC) 34. Each tuple of the relation body provides attribute values to instantiate the predicate by substituting each of its free variables . 35. Let " V " denote the set of all free variables that may occur in the set of all terms. 36. There is a one-to-one correspondence between the free variables of the predicate and the attribute names of the relation heading. 37. We see that we can restrict ? to be a " sentence ", that is, a formula with no free variables . 38. There is no exact structural equivalent in lambda calculus for " let " expressions that have free variables that are used recursively. 39. So the " vertical bar " operator has a sort of non-associativity, which is obviously related to the concept of free variables . 40. Their basic premise is to choose a free variable assignment that will satisfy the most already unsatisfied clauses in the Boolean expression.
