Where is this guarantee stated? I don't see anything on that page about a guarantee. Does the go spec make this guarantee? How do we know how the puzzle is exe

Where is this guarantee stated? I don't see anything on that page about a guarantee. Does the go spec make this guarantee? How do we know how the puzzle is executed? And if you're saying some guarantee exists that the last executes first, then the rest execute in order, that's empirically false: https://play.golang.org/p/3gV0TYG4GQW https://play.golang.org/p/3gV0TYG4GQW 1000 773 774 775 776 ...