Subtraction in ℤ/pℤ or in ℤ/pℤ[x]: -

### 6.34.3 Subtraction in ℤ/pℤ or in ℤ/pℤ[x]: -

The - operator subtracts two integers in ℤ/pℤ or two polynomials in ℤ/pℤ[x]. (See also Section 6.8.2.) For polynomial expressions, use the normal command to simplify.

Examples.

- For integers in ℤ/pℤ:
  Input:
  31%13-10%13
  Output:

  ⎛ ⎝ | −5 | ⎞ ⎠ | %13

- For polynomials with coefficients in ℤ/pℤ:
  Input:
  normal((11*x+5)%13-(8*x+6)%13)
  or:
  normal(11% 13*x+5%13-(8% 13*x+6%13))
  Output:

  ⎛ ⎝ | 3%13 | ⎞ ⎠ | x+ | ⎛ ⎝ | −1 | ⎞ ⎠ | %13