Fix typo in owl-building-blocks.md (#524)

docs/explanation/owl-building-blocks.md

@@ -4,6 +4,6 @@ Here we briefly list the building blocks that are used in OWL that enable reason
 | OWL                    | Semantics          | Example                                    |
 |------------------------|--------------------|--------------------------------------------|
 | instance or individual | A member of a set. | A person called `Mary` or a dog called `Fido`. |
-| class                  | A set of in dividuals. | The `Person` class consisting of persons or the `Dog` class consisting of dogs.|
+| class                  | A set of individuals. | The `Person` class consisting of persons or the `Dog` class consisting of dogs.|
 | object property | A set of pairs of individuals. | The `owns` object property can link a pet and its `owner: Mary owns Fido`.|
 | data property | A set of pairs where each pair consists of an individual linked to a data value.|The data property `hasAge` can link a number representing an age to an individual: `hasAge(Mary, 10)`.|