− — minus operator

1. Definition

Minus operator is inverse of the plus operator.

Zero minuend and zero subtrahend:

0 − a = −a
a − 0 = a

Negative subtrahend:

a − (−b) = a + b

Double subtraction:

a − b − c = a − (b + c)

Commutativity:

a − b − c = a − c − b
a + b − c = a − c + b

To subtract numbers:

7−2

To subtract complex numbers:

7+i*5−(2+i)

To engage current result as minuend or subtrahend:

rslt−2;
7−rslt;

To engage number z in memory as minuend or subtrahend:

mem[z]−2;
7−mem[z];

To subtract numbers z and w in memory:

mem[z]−mem[w];

Subtraction of complex numbers is supported in professional version of the Librow calculator.