ieja International Electronic Journal of Algebra 1306-6048 Abdullah HARMANCI A REIDEMEISTER-SCHREIER THEOREM FOR FINITELY L-PRESENTED GROUPS Hartung René 06 01 2012 11 11 125 159 06 01 2012 Copyright © 2007, International Electronic Journal of Algebra 2007 International Electronic Journal of Algebra

We prove a variant of the well-known Reidemeister-Schreier Theorem for finitely L-presented groups. More precisely, we prove that each finite index subgroup of a finitely L-presented group is itself finitely L-presented. Our proof is constructive and it yields a finite L-presentation for the subgroup. We further study conditions on a finite index subgroup of an invariantly finitely L-presented group to be invariantly L-presented itself.

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