lei federal no. 4.357

02:22 Jul 3, 2018 

I normally change the full stop to a comma in such cases. "4.357" is the number, and not the name, of the law (as the "no." in the source text makes clear) and this number in British English is written as "4,375", just as numbers of currency units need to have the full stop changed to a comma (and vice versa). For example, in British English we would not write "R$ 1.234.567,89". However, leaving the law number without any punctuation, it will not be ambiguous.