// Seven-segment-to-BCD simplified conversion, provided by Jeremy Lennert 

/* Problem A (extra credit) : define SevenSegmentToBCD */

SevenSegmentToBCD([s0, s1, s2, s3, s4, s5, s6]) => [
      s0 && s1 && s2 && s3,                            // u
      !s2 || (s0 && !s6) || (!s0 && s1),               // v
      (s0 && !s1) || (!s2 && s4),                      // w
      (!s0 && !s1) || (s0 && !s4)                      // x
      ];