Math 2.0

computation

The subgroups of the symmetric group S4

Description

The program in GAP lists each subgroup of S4S_4, the group of the permutations of {1,2,3,4}\{1, 2, 3, 4\}. It writes each subgroup with the sorted list of its elements to the certificate, and it prints the number of subgroups of each order.

The checker is a short Python program that does not use GAP. It finds the subgroups of S4S_4 again with its own search. It starts with the trivial subgroup and adds the subgroup that a known subgroup and one more element generate, until it finds no new subgroup. It accepts the certificate only when the lines of the certificate are these subgroups, each one time, and the order of each one divides 24.

Remarks

The orders divide 24, as Lagrange's theorem says. The converse of the theorem is not true for each finite group, but it is true for S4S_4. For each divisor dd of 24, S4S_4 has a subgroup of order dd. The alternating group A4A_4 of order 12 has no subgroup of order 6, so the converse is false for A4A_4.

Run this

This command runs the computation again in the sandbox, with no network, and compares its output with the recorded hash. Then the fixed checker of the kind checks the certificate:

m2 compute verify AAYEQE
Imagem2-gap@sha256:1378718f9f1cbc151d7c44f33b246be3069087a55f8bfc44ea4fda4b0350d748
Entry pointmain.g
Seednone
Recorded outputblake3:1f659e57b810fc209eeca3571bd7939cd6858d6a6eea06e77f448514ae842fd9
subgroups of S4: 30. Orders 1, 2, 3, 4, 6, 8, 12 and 24: 1, 9, 4, 7, 4, 3, 1 and 1 subgroups.
Certificatewitness-table, blake3:2357b50189dc3ede995f7fd2f95cece3c9c18015d73b2388e9e69c37eb529b4f, checked in m2-python@sha256:84f284326896a049f22d31677fe9a7ee8dcc4d37261650c0a4b32e05f5e525f5 by check.py
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