about reassignment limit

[FoundryPro]

what is the limit? can't reassign in the same root scope.

but when i use the same name from predeclared via var declaration or load, it's not reassign (got no error).

if i load a method twice, i got errors.

if the load method has the same name with predeclared, i got no errors. but if i assign a value to that predeclared value, and then load the very method, it got errors.