Grid/__init__.py
def matrix2d_flip_vertical(m, n, i, j):
    '''
    matrix2d_flip_vertical
    ======================
    mirror the matrix coordinate across the horizontal bisector.
    '''
    return (m-1-i, j)

    matrix2d_flip_vertical
    ======================
    mirror the matrix coordinate across the horizontal bisector.
    
matrix2d_flip_vertical
mirror the matrix coordinate across the horizontal bisector.
matrix2d_flip_vertical mirror the matrix coordinate across the horizontal bisector .
def matrix2d_flip_vertical(m, n, i, j):
    return (m-1-i, j)
def matrix2d_flip_vertical ( m , n , i , j ) : return ( m - 1 - i , j )
matrix2d_flip_vertical
mirror the matrix coordinate across the horizontal bisector.
matrix2d_flip_vertical mirror the matrix coordinate across the horizontal bisector .
'''
    matrix2d_flip_vertical
    ======================
    mirror the matrix coordinate across the horizontal bisector.
    '''
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