[request] [±] key, always as change of sign operator

[compsystems]

sorry for my bad English

Currently the unary operator CHange of Sign (CHS), function NEG() is operating only for numbers on entry line =(

the key [±] is associated with NEG() operator

neg(5) → -5 // ok
5[±] → -5
x [±] → x- // in this case acts as subtraction operator binary =(, and there is a dedicated key for subtraction [-],two keys for the same operation

My suggestion is that the key associated change of sign [±] always acts always as neg(), It is very useful to change the sign to an expression without having to be returned to the start of it, for example

(a-b) [±] → -(a-b) and not as (a-b)-