doc-src/Tutorial/Misc/InfixTree.ML

renamed norm_hhf to norm_hhf_rule;
removed slow rewrite_cterm;

Goal "!xs. linInfixList t xs = infixList t @ xs";
by(induct_tac "t" 1);
by(Simp_tac 1);
by(Asm_simp_tac 1);