(1) added axiom to ringb and theorems to enable algebra to prove the ideal membership problem; (2) Method algebra now calls algebra_tac which first tries to solve a universal formula, then in case of failure trie to solve the ideal membership problem (see HOL/Tools/Groebner_Basis/groebner.ML)
<?xml version="1.0"?>
<locatingRules xmlns="http://thaiopensource.com/ns/locating-rules/1.0">
<uri resource="pgip_isar.xml" uri="pgip.rnc"/>
<uri resource="pgip_isar.xml" typeId="RELAX NG"/>
</locatingRules>