def METHOD_NAME(a, x, dps=50, maxterms=10**8):
    """Compute gammaincc exactly like mpmath does but allow for more
    terms in hypercomb. See
    mpmath/functions/expintegrals.py#L187
    in the mpmath github repository.
    """
    with mp.workdps(dps):
        z, a = a, x
        if mp.isint(z):
            try:
                # mpmath has a fast integer path
                return mpf2float(mp.gammainc(z, a=a, regularized=True))
            except mp.libmp.NoConvergence:
                pass
        nega = mp.fneg(a, exact=True)
        G = [z]
        # Use 2F0 series when possible; fall back to lower gamma representation
        try:
            def h(z):
                r = z-1
                return [([mp.exp(nega), a], [1, r], [], G, [1, -r], [], 1/nega)]
            return mpf2float(mp.hypercomb(h, [z], force_series=True))
        except mp.libmp.NoConvergence:
            def h(z):
                T1 = [], [1, z-1], [z], G, [], [], 0
                T2 = [-mp.exp(nega), a, z], [1, z, -1], [], G, [1], [1+z], a
                return T1, T2
            return mpf2float(mp.hypercomb(h, [z], maxterms=maxterms))