t7290.scala:4: error: Pattern contains duplicate alternatives: 0
    case 0 | 0 => 0
         ^
t7290.scala:5: error: Pattern contains duplicate alternatives: 2, 3
    case 2 | 2 | 2 | 3 | 2 | 3 => 0
         ^
t7290.scala:6: error: Pattern contains duplicate alternatives: 4
    case 4 | (_ @ 4) => 0
         ^
three errors found