A presentation of a manifold by a crystallization has the following form (this is the connected sum of two lens spaces):
fabcdelghijkomn*onjihgfedcbmlka*jimolkdnbafechg
The code of a crystallization with 2n vertices consists of three words separated by *. The words must consist of the first n letters of the Roman alphabet. It is only allowed to use lower-case letters. Thus, the maximal number of vertices of any crystallization is 52. All three words should be placed in the same line.
Please notice that if the text in the current window contains more than one crystallization code then the program takes into account only the first one and ignores the rest.
Details on presenting manifolds by crystallizations can be found in [Crystal]. The program works by first constructing a special spine of the given manifold and then operating with it. This spine can be viewed at any moment by going to "Information|Show Boundary Curves".
Remark.
If the manifold determined by the crystallization is a connected sum, the program provides only the list of connected non-oriented summands (this is actually true for the other types of presentations as well). Therefore it is possible to get identical answers for non-homeomorphic connected sums. For example, the following two crystallization codes
fabcdelghijkomn*onjihgfedcbmlka*jimolkdnbafechg and fabcdelghijkomn*onjihgfedcbmlka*jinmlkdobafegch
correspond to non-homeomorphic connected sums of two copies of the lens space L(3,1). However, the result of the recognition in both cases is the same: A connected sum of 2 items : H_1=Z_3+Z_3 Item 1 - L(3,1) Item 2 - L(3,1)
[Crystal] M. Ferri, C. Gagliardi, L. Grasselli, A graph-theoretical representation of PL-manifolds: A survey on crystallizations, Aequat. Math. 31 (1986), 121–141.