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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def rej(vec, vec_onto):
 """ Vector rejection. Calculated by subtracting from `vec` the projection of `vec` onto `vec_onto`: .. math:: \\mathsf{vec} - \\mathrm{proj}\\left(\\mathsf{vec}, \\ \\mathsf{vec\\_onto}\\right) Parameters vec length-R |npfloat_| -- Vector to reject vec_onto length-R |npfloat_| -- Vector onto which `vec` is to be rejected Returns ------- rej_vec length-R |npfloat_| -- Rejection of `vec` onto `vec_onto` """


    # Imports
    import numpy as np

    # Calculate and return.
    rej_vec = vec - proj(vec, vec_onto)
    return rej_vec