Prolog

PART VI - Even-Odd

Example #1: Even-Odd

even[X]:-num[Y]*eval[X==2*Y].
odd[X]:-num[X]*~even[X].
num[1].
num[2].
num[3].
num[4].
num[5].
num[6].

Resolution Trace for Example #1:

odd[X]	num[X]	~even[X]	num[Y]	*eval[X==2Y]**
odd[A]
	num[A]
	A=1
		~even[1]
			num[Y]
			Y=1
				eval[1==2*1]
				FALSE
			num[Y] (#2)
			Y=2
				eval[1==2*2] (#2)
				FALSE
			<...>
		~even[1] (#2)
		FALSE
		>>_odd[1]
	num[A] (#2)
	A=2
		~even[2]
			num[Y]
			Y=1
				eval[2==2*1]
				TRUE
				>>_odd[2]
				eval[2==2*1] (#2)
				FALSE
			num[Y] (#2)
			Y=2
				eval[2==2*2]
				FALSE
			<...>
		~even[2] (#2)
		FALSE
		<<_odd[2]
	<...>
odd[A] (#2)
FALSE
<<_odd[1]
>>odd[1]
<<_odd[3]
>>odd[3]
<<_odd[5]
>>odd[5]

<Under Construction>

Next: Primes

Questions? Comments? Send them here. Or return to deXXed.