I was wondering whether there is a formal rule for or against substituting 'all' for 'both'?
We all know the difference between 'all' and 'both', but look at this question from ELL:
Here there are answers to the effect that both shall always refer to 2 things, and all can refer to more than one -- is that definition of 'all' widely accepted, and if it thus overlaps with 'both', can 'all' substitute for 'both' at least in certain cases?
Example 1 (2 is specified) :
he has 2 shirts -- both of them are white
he has 2 shirts; all of them are white
Example 2 (2 is implied) :
He crashed his bike. Both the wheels were smashed.
He crashed his bike. ALL the wheels were smashed.
I know that 'both' sounds better whetever clearly applicable, but can 'all' ever substitute for 'both', or is there a clear grammatical rule / convention that "thou shalt not use 'all' wherever 'both' is applicable?"