SparseMatrix = object
  ia*: seq[int]
  ja*: seq[int]
  aa*: seq[float]

DynamicVector = seq[float]

proc newVector(size: int): DynamicVector {...}{.raises: [], tags: [].}

proc size(vector: DynamicVector): int {...}{.raises: [], tags: [].}

proc `+`(a, b: DynamicVector): DynamicVector {...}{.raises: [], tags: [].}

proc `*`(a: float; b: DynamicVector): DynamicVector {...}{.raises: [], tags: [].}

proc `-`(a, b: DynamicVector): DynamicVector {...}{.raises: [], tags: [].}

proc dot(a, b: DynamicVector): float {...}{.raises: [], tags: [].}

proc norm(a: DynamicVector): float {...}{.raises: [], tags: [].}

proc setDiagonalRows(A: var SparseMatrix; rows: seq[int]) {...}{.raises: [], tags: [].}

proc `*`(A: SparseMatrix; b: DynamicVector): DynamicVector {...}{.raises: [],
    tags: [].}

proc rows(A: SparseMatrix): int {...}{.raises: [], tags: [].}

proc cols(A: SparseMatrix): int {...}{.raises: [], tags: [].}

proc `$`(A: SparseMatrix): string {...}{.raises: [], tags: [].}

proc getEntry(A: SparseMatrix; i, j: int): float {...}{.raises: [], tags: [].}

proc getIndex(A: SparseMatrix; i, j: int): int {...}{.raises: [], tags: [].}

proc nonzero_bounds_row(A: SparseMatrix; row: int): (int, int) {...}{.raises: [],
    tags: [].}

proc toCSR(Ai, Aj: seq[int]; Ax: seq[float]): SparseMatrix {...}{.raises: [],
    tags: [].}