  The combined universal probability $\mathbf{m}(D)$ of strings $x$ in sets $D$
is close to max $\mathbf{m}(x)$ over $x$ in $D$: their logs differ by at most
$D$'s information $\mathbf{I}(D:\mathcal{H})$ about the halting sequence
$\mathcal{H}$.
