Editing Probable prime (section)

===Example of testing for a strong probably prime===
To test whether 97 is a strong probable prime base 2:
* Step 1: Find <math>d</math> and <math>s</math> for which <math>96=d\cdot 2^s</math>, where <math>d</math> is odd
** Beginning with <math>s=0</math>, <math>d</math> would be <math>96</math>
** Increasing <math>s</math>, we see that <math>d=3</math> and <math>s=5</math>, since <math>96=3\cdot 2^5</math>
* Step 2: Choose <math>a</math>, <math>1 < a < 97 - 1</math>. We will choose <math>a = 2</math>.
* Step 3: Calculate <math>a^d \bmod n</math>, i.e. <math>2^3 \bmod 97</math>. Since it isn't congruent to <math>1</math>, we continue to test the next condition
* Step 4: Calculate <math>2^{3\cdot 2^r} \bmod 97</math> for <math>0 \leq r < s</math>. If it is congruent to <math>96</math>, <math>97</math> is probably prime. Otherwise, <math>97</math> is definitely composite
** <math>r=0: 2^3 \equiv 8 \pmod{97}</math>
** <math>r=1: 2^6 \equiv 64 \pmod{97}</math>
** <math>r=2: 2^{12} \equiv 22 \pmod{97}</math>
** <math>r=3: 2^{24} \equiv 96 \pmod{97}</math>
* Therefore, <math>97</math> is a strong probable prime base 2 (and is therefore a probable prime base 2).