>>
>>Metin,
>>
>>In algebra it is the same
>>
>>In computer language it's different: There's a unary and a binary minus with different precedence
>
>In new .NET (Oslo.SDK) there is M-grammar that allow to define your own grammar. Very cool and complex (for beginners like me) stuff. That was the topic of NY last .NET meetup.

Define your own grammar? That doesn't sound like such a good idea on the face of it, at least not if it allows you to change fundamentals rather than adding your own extensions.