Update applicator vocabulary description

The prior commits just moved this text over, this commit
updates the text to make sense for the new location and
structure.

In particular, this removes the focus on validation as the
applicator vocabulary is more fundamental.

Author: handrews

jsonschema-core.xml

@@ -973,38 +973,27 @@
 
         <section title="A Vocabulary for Applying Subschemas">
             <t>
-                Validation begins by applying the root schema to the complete instance
-                document.  From there, various keywords are used to determine which additional
-                subschemas are applied to either the current location, or a child location.
-                These keywords also define whether and how subschema assertion results are
-                modified and/or combined.  Such keywords do not assert conditions on their
-                own.  Rather, they control how assertions are applied and evaluated.
+                Evaluation of an instance against a schema begins by applying the root schema
+                to the complete instance document.  From there, various keywords are used
+                to determine which additional subschemas are applied to either the current
+                location, or a child location.  These keywords also define how subschema
+                assertion results are modified and/or combined.  Annotation results are
+                combined according to the rules specified by each annotation keyword.
             </t>
             <t>
-                The keywords in the <xref target="logic">boolean logic</xref> and
-                <xref target="conditional">conditional</xref> sections of this specification
-                apply subschemas to the same location as the parent schema.  The former group
-                defines boolean operations on the subschema assertion results, while the
-                latter evaluates one subschema and uses its assertion results to determine
-                which of two other subschemas to apply as well.
-            </t>
-            <t>
-                Several keywords determine which subschemas are applied to array items,
-                object property values, and object property names.  They are:
-                "items", "additionalItems", "contains", "properties", "patternProperties",
-                "additionalProperties", and "propertyNames".  The "contains" keyword only
-                requires its subschema to be valid against at least one child instance, while
-                the other keywords require that all subschemas are valid against all child
-                instances to which they apply.
+                Keyword that apply subschemas are called applicators, and do not assert
+                conditions on their own.  Rather, they control how assertions are applied
+                and evaluated.  This section defines a set of applicator keywords that
+                are RECOMMENDED for use as the basis of other vocabularies.
             </t>
             <section title="Keyword Independence">
                 <t>
-                    Validation keywords typically operate independently, without
+                    Schema keywords typically operate independently, without
                     affecting each other's outcomes.
                 </t>
                 <t>
                     For schema author convenience, there are some exceptions among the
-                    keywords that control subschema applicability:
+                    keywords in this vocabulary:
                     <list>
                         <t>
                             "additionalProperties", whose behavior is defined in terms of
@@ -1018,8 +1007,20 @@
             </section>
 
             <section title="Keywords for Applying Subschemas in Place">
+                <t>
+                    These keywords apply subschemas to the same location in the instance
+                    as the parent schema is being applied.  They allow combining
+                    or modifying the subschema results in various ways.
+                </t>
 
                 <section title="Keywords for Applying Subschemas With Boolean Logic" anchor="logic">
+                    <t>
+                        These keywords correspond to logical operators for combining or modifying
+                        the boolean assertion results of the subschemas.  They have no direct
+                        impact on annotation collection, although they enable the same annotation
+                        keyword to be applied to an instance location with different values.
+                        Annotation keywords define their own rules for combining such values.
+                    </t>
                     <section title="allOf">
                         <t>
                             This keyword's value MUST be a non-empty array.
@@ -1118,7 +1119,7 @@
                         </t>
                         <t>
                             When "if" is present, and the instance successfully
-                            validates against its subschema, then valiation
+                            validates against its subschema, then validation
                             succeeds against this keyword if the instance also
                             successfully validates against this keyword's subschema.
                         </t>
@@ -1136,7 +1137,7 @@
                         </t>
                         <t>
                             When "if" is present, and the instance fails to
-                            validate against its subschema, then valiation
+                            validate against its subschema, then validation
                             succeeds against this keyword if the instance
                             successfully validates against this keyword's subschema.
                         </t>
@@ -1151,6 +1152,11 @@
                 </section>
             </section>
             <section title="Keywords for Applying Subschemas to Child Instances">
+                <t>
+                    Each of these keywords defines a rule for applying its
+                    subschema(s) to child instances, specifically object
+                    properties and array items, and combining their results.
+                </t>
                 <section title="Keywords for Applying Subschemas to Arrays">
                     <section title="items">
                         <t>