assertThat("equivs set is empty", equivs.size(), greaterThan(0));
// test equivalencing
try {
// test parameter equivalencer
int params = p2.stage3EquivalenceParameters(pn, equivs);
assertThat("incorrect number of parmeter equivalences", params, is(9));
// test term equivalencer
int terms = p2.stage3EquivalenceTerms(pn);
assertThat("incorrect number of term equivalences", terms, is(5));