(sol, syms, func, funcarg)
return simplify(final.subs(eta, funcarg))
r"""
    Helper function to replace constants by functions in 1st_linear_variable_coeff
r"""
    Helper function to replace constants by functions in 1st_linear_variable_coeff
r Helper function to replace constants by functions in 1st_linear_variable_coeff
def _simplify_variable_coeff(sol, syms, func, funcarg):
    r"""
    Helper function to replace constants by functions in 1st_linear_variable_coeff
    """
    eta = Symbol("eta")
    if len(syms) == 1:
        sym = syms.pop()
        final = sol.subs(sym, func(funcarg))

    else:
        fname = func.__name__
        for key, sym in enumerate(syms):
            tempfun = Function(fname + str(key))
            final = sol.subs(sym, func(funcarg))

    return simplify(final.subs(eta, funcarg))
def _simplify_variable_coeff ( sol , syms , func , funcarg ) : eta = Symbol ( "eta" ) if len ( syms ) == 1 : sym = syms . pop ( ) final = sol . subs ( sym , func ( funcarg ) ) else : fname = func . __name__ for key , sym in enumerate ( syms ) : tempfun = Function ( fname + str ( key ) ) final = sol . subs ( sym , func ( funcarg ) ) return simplify ( final . subs ( eta , funcarg ) )