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Dear Gap-Forum,

I very much look forward to the inclusion of Akos Seress' fast random

algorithms for permutation groups into Gap 3.4, and can certainly wait

a while in order to make sure they are smoothly integrated into the

system.

However, if these algorithms are going to run without the user being

aware then they must provide a certain result when they return a result

at all. If there is some probability of the answer being wrong then

the user must be alerted to this fact, and hopefully also be provided

with the probability of an error. For example, if the group order is

said to be n, then for certain algorithms the order is at least n,

but may be greater than n with a small probability. Such functions

are very very useful when playing around in groups to, say, find a

subgroup of a given order, but in the end we must have a proof.

I expect these considerations have already been well thought out by

the Gap designers, but I just wanted to make my concerns clear.

When I use a function (such as the very useful but undocumented

MakeStabChainRandom in Gap 3.3), I always want to know precisely

to what extent the results are certain.

Sincerely, Leonard Soicher.

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