Is the language supposed to "validate"? In this file, there is no constraint describing non-negative number or non-empty string, or ill-formed URL, or invalid

Is the language supposed to "validate"? In this file, there is no constraint describing non-negative number or non-empty string, or ill-formed URL, or invalid number ports. EDIT : found it in the doc : https://cuelang.org/docs/usecases/validation/ https://cuelang.org/docs/usecases/validation/