ZF/indrule/mutual_ind_tac: backtracks using DEPTH_SOLVE to be certain of solving the subgoal.  Entire tactic is enclosed in DETERM to prevent backtracking between subgoals.
ZF/indrule/mutual_ind_tac: backtracks using DEPTH_SOLVE to be certain of
solving the subgoal.  Entire tactic is enclosed in DETERM to prevent
backtracking between subgoals.

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle