human
I wrote the below code

    def _sympified_list(w):
        return list(map(sympify, (w if iterable(w) else [w])))
    bare_f = (not iterable(f))
    ordered_symbols = (symbols and symbols[0] and (isinstance(symbols[0], Symbol) or is_sequence(symbols[0], include=GeneratorType)))
    (f, symbols) = (_sympified_list(w) for w in [f, symbols])
    implicit = flags.get('implicit', False)
    if (not symbols):
        symbols = set().union(*[fi.free_symbols for fi in f])
        if (len(symbols) < len(f)):
            for fi in f:
                pot = preorder_traversal(fi)
                for p in pot:
                    if isinstance(p, AppliedUndef):
                        flags['dict'] = True
                        symbols.add(p)
                        pot.skip()
        symbols = list(symbols)
        ordered_symbols = False
    elif ((len(symbols) == 1) and iterable(symbols[0])):
        symbols = symbols[0]
    exclude = flags.pop('exclude', set())
    if exclude:
        if isinstance(exclude, Expr):
            exclude = [exclude]
        exclude = set().union(*[e.free_symbols for e in sympify(exclude)])
    symbols = [s for s in symbols if (s not in exclude)]
    for (i, fi) in enumerate(f):
        if isinstance(fi, Equality):
            if ('ImmutableDenseMatrix' in [type(a).__name__ for a in fi.args]):
                f[i] = (fi.lhs - fi.rhs)
            else:
                f[i] = Add(fi.lhs, (- fi.rhs), evaluate=False)
        elif isinstance(fi, Poly):
            f[i] = fi.as_expr()
        elif (isinstance(fi, (bool, BooleanAtom)) or fi.is_Relational):
            return reduce_inequalities(f, symbols=symbols)
        f[i] = f[i].replace((lambda w: isinstance(w, HyperbolicFunction)), (lambda w: w.rewrite(exp)))
        if f[i].is_Matrix:
            bare_f = False
            f.extend(list(f[i]))
            f[i] = S.Zero
        freei = f[i].free_symbols
        if (freei and all(((s.is_real or s.is_imaginary) for s in freei))):
            (fr, fi) = f[i].as_real_imag()
            had = f[i].atoms(re, im, arg,...

What's a good function header?

Here's a good function header?
assistant
#Here's a good function header.

def solve(f, *symbols, **flags):