Use your knowledge of argument forms and the counterexample method to determine which, if any, of the following statements are true. Check all that apply. If two arguments are not substitution instances of the same argument form, then one argument cannot be a counterexample to the other. Since validity or invalidity is a matter of degree, being a counterexample is also a matter of degree. To be a successful counterexample, an argument must have a true conclusion. If you have made many unsuccessful attempts to come up with a counterexample to a given argument form, then the argument form in question is valid. An argument's form is determined by replacing the content words with letters, while leaving the form words alone. A successful counterexample may have true premises and a true conclusion. "If," "then," and "not" are typical form words for hypothetical syllogisms. A substitution instance is produced by uniformly substituting terms or statements for the letters in an argument form. Some argument forms are neither valid nor invalid. A successful counterexample will use statements with indisputable truth values and terms with precise definitions. If an argument is a substitution instance of a valid argument form and an invalid argument form, then the argument is invalid. In the form for a categorical syllogism, the letters represent statements. Any argument that can be produced by uniformly substituting terms or statements in place of the letters in an argument form is a substitution instance. An argument form is the same thing as a substitution instance. In an argument form for a categorical syllogism, the letters will stand for terms or noun phrases.