Standardise null, true, false formatting (#1270)

Author: JPryce-Aklundh

modules/ROOT/pages/appendix/gql-conformance/supported-mandatory.adoc

@@ -26,7 +26,7 @@ The below table is instead listed in order of their appearance in the link:https
 | xref:values-and-types/property-structural-constructed.adoc#property-types[Property types], xref:values-and-types/property-structural-constructed.adoc#type-synonyms[Types and their synonyms].
 | Includes: `BOOLEAN` (`BOOL`), `FLOAT`, `INTEGER` (`SIGNED INTEGER`, `INT`), and `STRING` (`VARCHAR`).
 
-Cypher supports the boolean type predicate for `TRUE`, `FALSE`, and `NULL` but does not support the GQL keyword `UNKNOWN`.
+Cypher supports the boolean type predicate for `true`, `false`, and `null` but does not support the GQL keyword `UNKNOWN`.
 
 | 9.1
 | <nested procedure specification>
@@ -138,7 +138,7 @@ This is currently not available in Cypher.
 
 | 19.5
 | <null predicate>
-| xref:expressions/predicates/type-predicate-expressions.adoc#type-predicate-null[Type predicate expressions for `NULL`]
+| xref:expressions/predicates/type-predicate-expressions.adoc#type-predicate-null[Type predicate expressions for `null`]
 |
 
 | 19.6
@@ -170,8 +170,8 @@ In Cypher, current user details can be seen using the link:{neo4j-docs-base-uri}
 | 20.9
 | <aggregate function>
 | xref:functions/aggregating.adoc#functions-avg[`avg()`], xref:functions/aggregating.adoc#functions-count[`count()`], xref:functions/aggregating.adoc#functions-max[`max`], xref:functions/aggregating.adoc#functions-mind[`min()`], xref:functions/aggregating.adoc#functions-sum[`sum()`]
-| Cypher and GQL handle `NULL` values differently for the `sum()` function when queries return 0 rows. 
-For example, `RETURN sum(<expr>)` on an empty table returns `NULL` in GQL, but in Cypher it returns `0`.
+| Cypher and GQL handle `null` values differently for the `sum()` function when queries return 0 rows. 
+For example, `RETURN sum(<expr>)` on an empty table returns `null` in GQL, but in Cypher it returns `0`.
 
 | 20.11
 | <property reference>

modules/ROOT/pages/appendix/gql-conformance/supported-optional.adoc

@@ -208,8 +208,8 @@ GQL also defines a parameterless version of the function not in Cypher: `CURRENT
 |
 
 | GV70
-| Immaterial value types: null type support (`NULL`)
-| xref:values-and-types/working-with-null.adoc[Working with `NULL`]
+| Immaterial value types: null type support (`null`)
+| xref:values-and-types/working-with-null.adoc[Working with `null`]
 |
 
 | GV71

modules/ROOT/pages/clauses/with.adoc

@@ -256,11 +256,11 @@ ORDER BY price
 |===
 | product | price | isAffordable | discountCategory
 
-| "Chocolate" | 5 | TRUE | 'Budget'
-| "Coffee" | 10 | TRUE | 'Budget'
-| "Headphones" | 250 | TRUE | 'Budget'
-| "Phone" | 500   | FALSE | 'High-end'
-| "Laptop" | 1000  | FALSE | 'High-end'
+| "Chocolate" | 5 | true | 'Budget'
+| "Coffee" | 10 | true | 'Budget'
+| "Headphones" | 250 | true | 'Budget'
+| "Phone" | 500   | false | 'High-end'
+| "Laptop" | 1000  | false | 'High-end'
 
 4+d|Rows: 5
 |===
@@ -395,9 +395,9 @@ RETURN c.firstName AS customer,
 |===
 | customer | totalSpent | topSpender
 
-| "Mateo" | 1015 | TRUE
-| "Amir"  | 1005 | TRUE
-| "Yusuf" | 1005 | TRUE
+| "Mateo" | 1015 | true
+| "Amir"  | 1005 | true
+| "Yusuf" | 1005 | true
 
 3+d|Rows: 3
 |===
@@ -423,10 +423,10 @@ RETURN c.firstName AS customer,
 |===
 | customer | totalSpent | topSpender
 
-| "Leila" | 1000 | FALSE
-| "Niko" | 760 | FALSE
-| "Hannah" | 260 | FALSE
-| "Keisha" | 250 | FALSE
+| "Leila" | 1000 | false
+| "Niko" | 760 | false
+| "Hannah" | 260 | false
+| "Keisha" | 250 | false
 
 3+d|Rows: 4
 |===

modules/ROOT/pages/deprecations-additions-removals-compatibility.adoc

@@ -2140,7 +2140,7 @@ Changes to the visibility of databases hosted on offline servers.
 
 For such databases:
 
-* The `address` column will return `NULL`.
+* The `address` column will return `null`.
 * The `currentStatus` column will return `unknown`.
 * The `statusMessage` will return `Server is unavailable`.
 

modules/ROOT/pages/expressions/list-expressions.adoc

@@ -167,7 +167,7 @@ RETURN 3 IN nestedList[0] AS elementPresent
 |===
 
 
-Attempting to reference an element outside the bounds of the `LIST` will return `NULL`, as will attempting to access elements from an empty `LIST`.
+Attempting to reference an element outside the bounds of the `LIST` will return `null`, as will attempting to access elements from an empty `LIST`.
 
 .Out-of-bounds and empty `LIST` access
 [source, cypher]
@@ -181,7 +181,7 @@ RETURN list[5] AS outOfBound, emptyList[0] AS emptyAccess
 |===
 | outOfBound | emptyAccess
 
-| NULL | NULL
+| null | null
 
 2+d|Rows: 1
 |===
@@ -340,9 +340,9 @@ RETURN cecil.skills || cecilia.skills AS combinedSkills
 1+d|Rows: 1
 |===
 
-If `NULL` is part of a concatenated `LIST`, `NULL` will be a part of the new `LIST`.
+If `null` is part of a concatenated `LIST`, `null` will be a part of the new `LIST`.
 
-.Concatenate `LIST` including `NULL`
+.Concatenate `LIST` including `null`
 [source, cypher]
 ----
 RETURN [1, 2] || [3, null] AS listWithNull
@@ -353,12 +353,12 @@ RETURN [1, 2] || [3, null] AS listWithNull
 |===
 | listWithNull
 
-| [1, 2, 3, NULL]
+| [1, 2, 3, null]
 
 1+d|Rows: 1
 |===
 
-For removing `NULL` values when concatenating `LIST` values, see xref:expressions/list-expressions.adoc#null-list-concatenation-list-comprehension[`NULL`, list concatenation, and list comprehension].
+For removing `null` values when concatenating `LIST` values, see xref:expressions/list-expressions.adoc#null-list-concatenation-list-comprehension[`null`, list concatenation, and list comprehension].
 
 [[add-elements]]
 == Add elements to a list 
@@ -562,9 +562,9 @@ RETURN [person IN collect(p) WHERE 'Python' IN person.skills | person.name] AS p
 1+d|Rows: 1
 |===
 
-List comprehension can be used to remove any unknown `NULL` values when concatenating `LIST` values.
+List comprehension can be used to remove any unknown `null` values when concatenating `LIST` values.
 
-.List comprehension to remove `NULL` values during list concatenation
+.List comprehension to remove `null` values during list concatenation
 // tag::expressions_list_comprehension_concatenation_remove_null[]
 [source, cypher]
 ----

modules/ROOT/pages/expressions/map-expressions.adoc

@@ -228,7 +228,7 @@ RETURN p[dynamicValue] AS names
 1+d|Rows: 2
 |===
 
-Referencing a non-existent key in the `MAP` with the `[]` operator  will return `NULL`.
+Referencing a non-existent key in the `MAP` with the `[]` operator  will return `null`.
 
 .Dynamically referencing a non-existent `MAP` key
 [source, cypher]
@@ -243,7 +243,7 @@ RETURN map[dynamicKey] AS dynamicValue
 |===
 | dynamicValue
 
-| NULL
+| null
 
 1+d|Rows: 1
 |===
@@ -271,7 +271,7 @@ mapVariable {mapElement [, ...n]}
 
 [NOTE]
 The key names in a map must be of type `STRING`. +
-If `mapVariable` is `NULL`, the projection evaluates to `NULL`.
+If `mapVariable` is `null`, the projection evaluates to `null`.
 
 .Map projection with a key selector
 =====

modules/ROOT/pages/expressions/node-relationship-operators.adoc

@@ -133,16 +133,16 @@ RETURN p[$propertyName] AS middleName
 
 | "Catherine"
 | "David"
-| NULL
+| null
 
 1+d|Rows: 3
 |===
 
-== Handling `NULL` values
+== Handling `null` values
 
-If a property (or property value) is missing in an expression that uses tries to access a property statically or dynamically, the whole expression will evaluate to `NULL`.
+If a property (or property value) is missing in an expression that uses tries to access a property statically or dynamically, the whole expression will evaluate to `null`.
 The query below performs a xref:expressions/string-operators.adoc[string concatentation] on the `firstName`, `middleName`, and `lastName` properties on `Person` nodes.
-Note that `NULL` is returned for `Cecilia`, who lacks a `middleName` property.
+Note that `null` is returned for `Cecilia`, who lacks a `middleName` property.
 
 .String concatenation using node properties
 [source, cypher]
@@ -158,15 +158,15 @@ RETURN p.firstName || ' ' || p.middleName || ' ' || p.lastName AS fullName
 
 | "Alice Catherine Baxter"
 | "Cecil David Ericson"
-| NULL
+| null
 
 1+d|Rows: 3
 |===
 
-The xref:functions/scalar.adoc#functions-coalesce[`coalesce()`] function can be used to skip the first `NULL` values in an expression.
-In the below example, it replaces the first `NULL` value found with an empty `STRING`.
+The xref:functions/scalar.adoc#functions-coalesce[`coalesce()`] function can be used to skip the first `null` values in an expression.
+In the below example, it replaces the first `null` value found with an empty `STRING`.
 
-.Use the `coalesce()` function to skip `NULL` values
+.Use the `coalesce()` function to skip `null` values
 // tag::expressions_node_relationship_operators_null[]
 [source, cypher]
 ----

modules/ROOT/pages/expressions/predicates/boolean-operators.adoc

@@ -14,15 +14,15 @@ Cypher contains the following boolean operators:
 [options="header", cols="^,^,^,^,^,^", width="85%"]
 |===
 |a | b | a `AND` b | a `OR` b | a `XOR` b | `NOT` a
-|`FALSE` | `FALSE` | `FALSE` | `FALSE` | `FALSE` | `TRUE`
-|`FALSE` | `NULL` | `FALSE` | `NULL` | `NULL` | `TRUE`
-|`FALSE` | `TRUE` | `FALSE` | `TRUE` | `TRUE` | `TRUE`
-|`TRUE` | `FALSE` | `FALSE` | `TRUE` | `TRUE` | `FALSE`
-|`TRUE` | `NULL` | `NULL` | `TRUE` | `NULL` | `FALSE`
-|`TRUE` | `TRUE` | `TRUE` | `TRUE` | `FALSE` | `FALSE`
-|`NULL` | `FALSE` | `FALSE` | `NULL` | `NULL` | `NULL`
-|`NULL` | `NULL` | `NULL` | `NULL` | `NULL` | `NULL`
-|`NULL` | `TRUE` | `NULL` | `TRUE` | `NULL` | `NULL`
+|`false` | `false` | `false` | `false` | `false` | `true`
+|`false` | `null` | `false` | `null` | `null` | `true`
+|`false` | `true` | `false` | `true` | `true` | `true`
+|`true` | `false` | `false` | `true` | `true` | `false`
+|`true` | `null` | `null` | `true` | `null` | `false`
+|`true` | `true` | `true` | `true` | `false` | `false`
+|`null` | `false` | `false` | `null` | `null` | `null`
+|`null` | `null` | `null` | `null` | `null` | `null`
+|`null` | `true` | `null` | `true` | `null` | `null`
 |===
 
 [[example-graph]]

modules/ROOT/pages/expressions/predicates/index.adoc

@@ -1,7 +1,7 @@
 = Predicates
 :Description: Overview of the predicate expressions in Cypher.
 
-Predicates evaluate to a `BOOLEAN` value (`TRUE`, `FALSE`, or `NULL`), and are frequently used for filtering in xref:clauses/where.adoc[`WHERE`] subclauses.
+Predicates evaluate to a `BOOLEAN` value (`true`, `false`, or `null`), and are frequently used for filtering in xref:clauses/where.adoc[`WHERE`] subclauses.
 
 This chapter is divided into the following sections:
 

modules/ROOT/pages/expressions/predicates/list-operators.adoc

@@ -112,7 +112,7 @@ Only `Cecilia` is returned because she shares a `role` with `Cecil` (no `Person`
 =====
 
 The presence of duplicate values in a `LIST` does not affect the result of the `IN` operator, which checks whether an element appears at least once.
-For example, the below query returns `TRUE` (two `Person` nodes are `39` years old).
+For example, the below query returns `true` (two `Person` nodes are `39` years old).
 
 .Membership check in a `LIST` with duplicate values
 [source, cypher]
@@ -127,7 +127,7 @@ RETURN 39 IN allAges AS listWithDuplicates
 |===
 | listWithDuplicates
 
-| TRUE
+| true
 
 1+d|Rows: 1
 |===
@@ -136,33 +136,33 @@ RETURN 39 IN allAges AS listWithDuplicates
 
 
 [[null-behavior]]
-== `NULL` behavior
+== `null` behavior
 
-When `NULL` is involved in a membership check, the result is will be `NULL`.
+When `null` is involved in a membership check, the result is will be `null`.
 
-.Using the `IN` operator with `NULL`
+.Using the `IN` operator with `null`
 [source, cypher]
 ----
-RETURN NULL IN [1, 2, NULL] AS nullInList, 123 IN NULL AS valueInNull
+RETURN null IN [1, 2, null] AS nullInList, 123 IN null AS valueInNull
 ----
 
 .Result
 [role="queryresult",options="header,footer",cols="2*<m"]
 |===
 | nullInList | valueInNull 
 
-| NULL | NULL
+| null | null
 
 2+d|Rows: 1
 |===
 
-To check if `NULL` is a member of a `LIST`, use the xref:functions/predicate.adoc#functions-any[`any()`] function:
+To check if `null` is a member of a `LIST`, use the xref:functions/predicate.adoc#functions-any[`any()`] function:
 
-.Checking if `NULL` is a member of a `LIST`
+.Checking if `null` is a member of a `LIST`
 // tag::expressions_predicates_list_operators_check_null[]
 [source, cypher]
 ----
-RETURN any(x IN [1, 2, NULL] WHERE x IS NULL) AS containsNull
+RETURN any(x IN [1, 2, null] WHERE x IS NULL) AS containsNull
 ----
 // end::expressions_predicates_list_operators_check_null[]
 
@@ -171,7 +171,7 @@ RETURN any(x IN [1, 2, NULL] WHERE x IS NULL) AS containsNull
 |===
 | containsNull
 
-| TRUE
+| true
 
 1+d|Rows: 1
 |===
@@ -180,7 +180,7 @@ RETURN any(x IN [1, 2, NULL] WHERE x IS NULL) AS containsNull
 == Nested lists
 
 When used with nested `LIST` values, the `IN` operator evaluates whether a `LIST` is an exact match to any of the nested `LIST` values that are part of an outer `LIST`.
-Partial matches of individual elements within a nested `LIST` will return `FALSE`.
+Partial matches of individual elements within a nested `LIST` will return `false`.
 
 .Checking for membership in nested `LIST` values
 [source, cypher]
@@ -193,7 +193,7 @@ RETURN [0, 2] IN [[1, 2], [3, 4]] AS listInNestedList
 |===
 | listInNestedList
 
-| FALSE
+| false
 
 1+d|Rows: 1
 |===
@@ -212,7 +212,7 @@ RETURN [3, 4] IN [[1, 2], [3, 4]] AS listInNestedList
 |===
 | listInNestedList
 
-| TRUE
+| true
 
 1+d|Rows: 1
 |===
@@ -229,7 +229,7 @@ RETURN [1] IN [[1, 2], [3, 4]] AS listInNestedTest
 |===
 | listInNestedList
 
-| FALSE
+| false
 
 1+d|Rows: 1
 |===
@@ -249,14 +249,14 @@ RETURN all(x IN sub WHERE x IN list) AS subInList
 ----
 // end::expressions_predicates_list_operators_list_subset[]
 
-This returns `TRUE` because all elements in `sub` are part of `list`.
+This returns `true` because all elements in `sub` are part of `list`.
 
 .Result
 [role="queryresult",options="header,footer",cols="1*<m"]
 |===
 | subInList
 
-| TRUE
+| true
 
 1+d|Rows: 1
 |===
@@ -268,14 +268,14 @@ WITH [1,3,9] AS sub, [3,5,1,7,6,2,8,4] AS list
 RETURN all(x IN sub WHERE x IN list) AS subInList
 ----
 
-This returns `FALSE` because all elements in `sub` are not part of `list`.
+This returns `false` because all elements in `sub` are not part of `list`.
 
 .Result
 [role="queryresult",options="header,footer",cols="1*<m"]
 |===
 | subInList
 
-| FALSE
+| false
 
 1+d|Rows: 1
 |===