He invented it for algol, a language with sufficient complexity that it was basically impossible to implement. The process of creating c involved stripping off everything but the most necessary features. Null references made it, nullable types likely wouldn't have.
> The process of creating c involved stripping off everything but the most necessary features. Null references made it, nullable types likely wouldn't have.
Nonsense.
The entire point of Hoare's design was to have type safe references, which C pointers most definitely are not. The entire point of references was that they not be pointers.
