CCCatalytic branching programs (catalytic bps) compute the same
n
-bit boolean function
f
at multiple entry points that need to be remembered at the exit nodes of the bp. When a doubly exponential number of entry points is allowed, linear amortized catalytic bp size is known to be achievable for any
f
. Here a method is introduced that produces a catalytic bp out of a reversible bp and a deterministic dag-like communication protocol. In a multiplicity range as low as linear,
approximating
a threshold is shown possible at linear amortized cost. In the same low range,
computing
\(\texttt {Maj} \)
and
\(\texttt {Mod} \)
are shown possible at a cost that beats the brute force repetition of the best known bp for these functions by a polylog factor. In the exponential range, the method yields
O
(
n
log
n
) amortized cost for any symmetric function.