+let position_prefix = "http://www.cs.unibo.it/helm/schemas/schema-helm#"
+(* let position_prefix = "" *)
+
+let inconcl_pos = position_prefix ^ "InConclusion"
+let mainconcl_pos = position_prefix ^ "MainConclusion"
+let mainhyp_pos = position_prefix ^ "MainHypothesis"
+let inhyp_pos = position_prefix ^ "InHypothesis"
+let inbody_pos = position_prefix ^ "InBody"
+