>>>>

>>>>* this is ok
>>>>? 10-3-2
>>>>* typo 3 => bad result (better a syntax error !)
>>>>? 10--2
>>>>* Need a constraint in the grammar
>>>>? 10-(-2)
>>>>

>>>
>>>Why would that be wrong? If I substract 10 minus negative two, that is the same as 10 plus 2. What do you expect, and why?
>>
>>Of course, but the question is how you should write this.
>>With 3 or more signs VFP fail! VFP requires brackets.
>>I'd rather the obligation of the brackets with 2 signs too.
>>
>>Why this allow a small typo to create a valid expression,
>>but that is a calculation that the programmer did not want to do!
>>This may result in errors discovered after months,
>>you have lots of corrupted data
>>and to find the wrong expression you become crazy.
>>
>>The only help they can give you the language of development is the syntax,
>>I prefer a rigid syntax, to avoid a future in a mental hospital.
>
>So you're asking for is a change in grammar in the special case of a subtraction so that a unary minus will be forbidden on the right-hand side?
>
>i.e. the following will generate error
>? a --b
>? a - -b
>but these won't
>? a+-b
>? a*-b
>? a/-b
>? a%-b
>? a^-b

My ask is for unary minus or plus within brackets when before there is a aritmetic operator

>i.e. the following will generate error
>? a --b
>? a - -b
>but these too
>? a+-b
>? a*-b
>? a/-b
>? a%-b
>? a^-b

this is my ask
? a -(-b)
>? a -(-b)
>? a+(-b)
>? a*(-b)
>? a/(-b)
>? a%(-b)
>? a^(-b)

then this return error
? a(-b)

This reduces the chances of a typo run into the application.