fixup concepts

Author: jensmaurer

source/exec.tex

@@ -1059,7 +1059,7 @@
     concept @\deflibconcept{receiver}@ =
       @\libconcept{derived_from}@<typename remove_cvref_t<Rcvr>::receiver_concept, receiver_t> &&
       requires(const remove_cvref_t<Rcvr>& rcvr) {
-        { get_env(rcvr) } -> queryable;
+        { get_env(rcvr) } -> @\exposconcept{queryable}@;
       } &&
       @\libconcept{move_constructible}@<remove_cvref_t<Rcvr>> &&       // rvalues are movable, and
       @\libconcept{constructible_from}@<remove_cvref_t<Rcvr>, Rcvr>;   // lvalues are copyable
@@ -1828,7 +1828,7 @@
 to communicate to users why.
 
 \begin{itemdecl}
-template<sender Sndr, queryable Env>
+template<@\libconcept{sender}@ Sndr, @\exposconcept{queryable}@ Env>
   constexpr auto @\exposid{write-env}@(Sndr&& sndr, Env&& env);     // \expos
 \end{itemdecl}