[concepts.{lang,compare,callable}.general] Replace "section" with "subclause".

Author: timsong-cpp

source/concepts.tex

@@ -258,7 +258,7 @@
 \rSec2[concepts.lang.general]{General}
 
 \pnum
-This section contains the definition of concepts corresponding to language
+This subclause contains the definition of concepts corresponding to language
 features. These concepts express relationships between types, type
 classifications, and fundamental type properties.
 
@@ -740,7 +740,7 @@
 \rSec2[concepts.compare.general]{General}
 
 \pnum
-This section describes concepts that establish relationships and orderings
+This subclause describes concepts that establish relationships and orderings
 on values of possibly differing object types.
 
 \rSec2[concept.boolean]{Concept \libconcept{Boolean}}
@@ -1000,7 +1000,7 @@
 \rSec2[concepts.callable.general]{General}
 
 \pnum
-The concepts in this section describe the requirements on function
+The concepts in this subclause describe the requirements on function
 objects\iref{function.objects} and their arguments.
 
 \rSec2[concept.invocable]{Concept \libconcept{Invocable}}