STO-

Member Of Menu: 
Store
Argument Types: 
Real
Complex
Integer
Symbol
Array
Result Type(s): 
None
Invertible: 
No
Valid In Expression: 
No
Stack Diagram: 
Symbol1 Real2 →
Symbol1 Complex2 →
Symbol1 Integer2 →
Symbol1 Array2 →
Real1 Symbol2 →
Complex1 Symbol2 →
Integer1 Symbol2 →
Array1 Symbol2 →

This operation takes a symbol and another item of just about any numeric type (real, complex, integer or matrix). The symbol can be in either position on the stack and the other item on the stack must be a numeric input. It gets the value of that symbol from the current directory and performs the subtract operation.

If the symbol is in stack level 1, then the value of the symbol is subtracted from the numeric argument from stack level 2. If the symbol is in stack level 2, then the numeric argument from stack level 1 is subtracted from the value of the symbol. Either way, the result of that operation is stored back to the symbol. The old value of the symbol is replaced with the new calculated value. Nothing is returned on the stack because the result is stored in the symbol.