Undefined type in a signature
type.undefined
Message
Undefined type '<T>' in signature for '<name>'.
What it means
A (: ...) signature names a type that is neither a standard type nor declared or imported.
Why it happens
The type name is misspelled, or the module declaring it is not imported.
How to fix it
Use a known type, declare the type, or import the module that defines it.
metta
(: f (-> Numbr Number)) ; type.undefined: 'Numbr'Controlled by the metta.diagnostics.undefinedTypes setting.