Triangle, function            Tb

        s =. ( a + b + c ) % 2
        a < s
        b < s
        c < s

Solution 1, function with explicit definition

   Ttest =. ' *. / y. < s =. 0.5 * +/ y. ' : ''

   Ttest 1 1 2
0
   Ttest 1 1 2 + 0.001
1
   Ttest 3 4 5
1
   Ttest 3 4 5 - 2
0
   Ttest 3 4 5 - 1.999
1

