* doc/tl/tl.tex, src/ltlast/atomic_prop.cc, src/ltlast/binop.cc,
src/ltlast/bunop.cc, src/ltlast/constant.cc, src/ltlast/formula.cc,
src/ltlast/formula.hh, src/ltlast/multop.cc, src/ltlast/unop.cc:
Remove is_eltl_formula().
* src/tests/kind.test: Adjust.