gap-packages / sgpdec

GAP package for Hierarchical Composition and Decomposition of Permutation Groups and Transformation Semigroups
https://gap-packages.github.io/sgpdec/
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AsCascade applied to a permutation should return a permutation cascade #24

Open nehaniv opened 2 years ago

nehaniv commented 2 years ago

AsCascade applied to permutation must return a perm cascade but returns a transformation cascade instead. This leads to incorrect failures of equality checking, etc:

Example: gap> t := Cascade([5,5],[ [ [],(1,2,3,4,5)]]); <perm cascade with 2 levels with (5, 5) pts, 1 dependencies> gap> t_perm := AsPermutation(t);
(1,6,11,16,21)(2,7,12,17,22)(3,8,13,18,23)(4,9,14,19,24)(5,10,15,20,25) gap> t_perm_casc := AsCascade(t_perm,[5,5]); <trans cascade with 2 levels with (5, 5) pts, 1 dependencies> gap> Display(t); Dependency function of depth 1 with 1 dependencies. [ ] -> (1,2,3,4,5) Dependency function of depth 2 with 0 dependencies. gap> Display(t_perm_casc); Dependency function of depth 1 with 1 dependencies. [ ] -> Transformation( [ 2, 3, 4, 5, 1 ] ) Dependency function of depth 2 with 0 dependencies. gap> t = t_perm_casc; false

Result should be true.