[STATEMENT]
lemma subst_cls_lists_tl[simp]: "length Cs = length \<sigma>s \<Longrightarrow> tl (Cs \<cdot>\<cdot>cl \<sigma>s) = tl Cs \<cdot>\<cdot>cl tl \<sigma>s"
[PROOF STATE]
proof (prove)
goal (1 subgoal):
 1. length Cs = length \<sigma>s \<Longrightarrow> tl (Cs \<cdot>\<cdot>cl \<sigma>s) = tl Cs \<cdot>\<cdot>cl tl \<sigma>s
[PROOF STEP]
by (cases Cs; cases \<sigma>s) auto