type Row {
  label: Text
  count: Int
  other: Int
}

type Nested {
  row: Row
  label: Text
}

change(state: Row, delta: Int) (answer: Row) {
  answer = state
  answer.count = state.count + delta
  answer.other = state.other + answer.count
  answer.label = state.label + "!"
}

keepOld(state: Row) (answer: Row) {
  answer = state
  answer.count = 99
  answer.other = state.count
}

total(state: Row) (answer: Int) {
  answer = state.count
}

keepWhole(state: Row) (answer: Row) {
  answer = state
  answer.count = 99
  answer.other = total(state)
}

readWhole(state: Row) (answer: Row) {
  answer = state
  answer.count = total(state) + 1
}

changeSource(state: Row) (answer: Row) {
  answer = state
  state.count = 99
  answer.other = state.count
}

changeNested(state: Nested) (answer: Nested) {
  answer = state
  answer.row.count = state.row.count + 1
  answer.row.other = state.row.count
  answer.label = state.label + "!"
}

faultEntry() (answer: Row) {
  answer = change(Row { label = "x"
 count = 9223372036854775807
 other = 0 }, 1)
}

fieldValues() (answer: Bool) {
  source = Nested { row = Row { label = "雪", count = 7, other = 9 }, label = "外" }
  moved = Nested { label = source.label, row = source.row }
  answer = moved.label == "外" and moved.row.label == "雪"
  source = Nested { row = Row { label = "重叠", count = 3, other = 5 }, label = "未使用" }
  overlap = Nested { row = source.row, label = source.row.label }
  answer = answer and overlap.row.label == "重叠" and overlap.label == "重叠"
  row = Row { label = "借用", count = 11, other = 13 }
  borrowed = Row { label = row.label, count = total(row), other = row.other }
  answer = answer and borrowed.label == "借用" and borrowed.count == 11 and borrowed.other == 13
  row = Row { label = "保留", count = 17, other = 19 }
  copied = Row { label = row.label, count = row.count, other = row.other }
  row.label = "新值"
  answer = answer and copied.label == "保留" and row.label == "新值"
}

verify() (answer: Bool) {
  original = Row { label = "雪"
    count = 7
    other = 9 }
  changed = change(original, 2)
  answer = changed.label == "雪!" and changed.count == 9 and changed.other == 18
  answer = answer and original.label == "雪" and original.count == 7 and original.other == 9
  answer = answer and keepOld(original).other == 7 and keepWhole(original).other == 7
  answer = answer and readWhole(original).count == 8 and changeSource(original).other == 99
  temporary = keepOld(Row { label = "x"
    count = 3
    other = 0 })
  answer = answer and temporary.count == 99 and temporary.other == 3
  temporary = keepWhole(Row { label = "x"
    count = 4
    other = 0 })
  answer = answer and temporary.other == 4
  temporary = readWhole(Row { label = "x"
    count = 5
    other = 0 })
  answer = answer and temporary.count == 6
  nested = Nested { row = original
    label = "outer" }
  result = changeNested(nested)
  answer = answer and result.row.count == 8 and result.row.other == 7 and result.label == "outer!"
  answer = answer and nested.row.count == 7 and nested.row.other == 9 and nested.label == "outer"
  answer = answer and fieldValues()
}