doc-src/Tutorial/Misc/InfixTree.ML

A new approach, using simp_of_act and simp_of_set to activate definitions when
necessary

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