raiseBk :: SyntaxTree -> SyntaxTree
raiseBk = raise ((`elem` [
                          "definitions list",
                          "single definition",
                          "syntactic factor",
                          "syntactic primary",
                          "syntactic exception",
                          "syntactic term",
                          "integer"
                         ]) . identifier)
raiseBk :: SyntaxTree -> SyntaxTree
raiseBk = raise ((`elem` [
                          "definitions list",
                          "single definition",
                          "syntactic factor",
                          "syntactic primary",
                          "syntactic exception",
                          "syntactic term",
                          "integer"
                         ]) . identifier)
raiseBk = raise ((`elem` [
                          "definitions list",
                          "single definition",
                          "syntactic factor",
                          "syntactic primary",
                          "syntactic exception",
                          "syntactic term",
                          "integer"
                         ]) . identifier)