This field is required and in this only alphabets are allowed.
{{userFormGroup.controls.firstName.errors.compose.message}}
If you want to apply conditional validation on 'City' then you need to add 'First Name' input as 'Bharat'.
Conditional Expression with type 'string'
{{userFormGroup.controls.city.errors.compose.message}}
If you want to apply conditional validation on 'Age' then you need to add 'First Name' input as 'Bharat'.
Conditional Expression with type 'function'
{{userFormGroup.controls.age.errors.compose.message}}