public override StateFormula existentialNormalForm()
{
//EF phi = E (true U phi)
StateFormula true_state = new SBoolean(true);
StateFormula phi = operand.existentialNormalForm();
return(new SEUntil(true_state, phi));
}
public override StateFormula existentialNormalForm()
{
// AG phi = NOT EF (NOT phi) = NOT E (true U (NOT phi))
StateFormula e_operand = operand.existentialNormalForm();
StateFormula not_phi = new SNot(e_operand);
StateFormula true_state = new SBoolean(true);
StateFormula exists_until = new SEUntil(true_state, not_phi);
return(new SNot(exists_until));
}