Textile systems, coloured graphs and their applications to higher-rank graphs

We compute a presentation of the fundamental group of a higher-rank graph using a coloured graph description of higher-rank graphs developed by the third author. We show that textile systems may be thought of as generalisations of $2$-graphs. We define the fundamental, homology and cohomology groups of a textile system generalising those for rank-$2$ graphs. Our new approach to provides a tractable description of the funadmental group and second cohomology group of a textile system.