diff --git a/src/main/java/de/tla2b/analysis/SymbolRenamer.java b/src/main/java/de/tla2b/analysis/SymbolRenamer.java
index 8d1c8e84ab5b7887328cb9dadddaa5668beafb1c..122284b08ed7edf69075e3d00005100022bee60c 100644
--- a/src/main/java/de/tla2b/analysis/SymbolRenamer.java
+++ b/src/main/java/de/tla2b/analysis/SymbolRenamer.java
@@ -5,11 +5,12 @@ import de.tla2b.global.TranslationGlobals;
 import tla2sany.semantic.*;
 import tlc2.tool.BuiltInOPs;
 
+import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Hashtable;
+import java.util.Map;
 import java.util.Set;
 
-public class SymbolRenamer extends BuiltInOPs implements TranslationGlobals, ASTConstants {
+public class SymbolRenamer extends BuiltInOPs implements TranslationGlobals {
 
 	private final static Set<String> KEYWORDS = new HashSet<>();
 
@@ -66,7 +67,7 @@ public class SymbolRenamer extends BuiltInOPs implements TranslationGlobals, AST
 		KEYWORDS.add("OPERATIONS");
 	}
 
-	private final static Hashtable<String, String> INFIX_OPERATOR = new Hashtable<>();
+	private final static Map<String, String> INFIX_OPERATOR = new HashMap<>();
 
 	static {
 		INFIX_OPERATOR.put("!!", "exclamationmark2");
@@ -89,7 +90,7 @@ public class SymbolRenamer extends BuiltInOPs implements TranslationGlobals, AST
 		INFIX_OPERATOR.put("...", "dot3");
 	}
 
-	private final static Hashtable<String, String> BBUILTIN_OPERATOR = new Hashtable<>();
+	private final static Map<String, String> BBUILTIN_OPERATOR = new HashMap<>();
 
 	static {
 		BBUILTIN_OPERATOR.put("+", "plus");
@@ -110,7 +111,7 @@ public class SymbolRenamer extends BuiltInOPs implements TranslationGlobals, AST
 	private final Set<OpDefNode> usedDefinitions;
 
 	private final Set<String> globalNames = new HashSet<>();
-	private final Hashtable<OpDefNode, Set<String>> usedNamesTable = new Hashtable<>();
+	private final Map<OpDefNode, Set<String>> usedNamesTable = new HashMap<>();
 
 	private SymbolRenamer(ModuleNode moduleNode, SpecAnalyser specAnalyser) {
 		this.moduleNode = moduleNode;
diff --git a/src/main/java/de/tla2b/global/BBuiltInOPs.java b/src/main/java/de/tla2b/global/BBuiltInOPs.java
index 9fdc564cc960817fa56dfd54a2c2469c576c787b..163e30f921c5a702e77544beb1aad04d33afdb90 100644
--- a/src/main/java/de/tla2b/global/BBuiltInOPs.java
+++ b/src/main/java/de/tla2b/global/BBuiltInOPs.java
@@ -6,62 +6,61 @@ import java.util.HashMap;
 import java.util.Map;
 
 public class BBuiltInOPs implements BBuildIns {
-	private static final Map<UniqueString, Integer> B_Opcode_Table;
+	private static final Map<UniqueString, Integer> B_Opcodes = new HashMap<>();
 
 	static {
-		B_Opcode_Table = new HashMap<>();
-		B_Opcode_Table.put(OP_dotdot, B_OPCODE_dotdot);
-		B_Opcode_Table.put(OP_plus, B_OPCODE_plus);
-		B_Opcode_Table.put(OP_minus, B_OPCODE_minus);
-		B_Opcode_Table.put(OP_times, B_OPCODE_times);
-		B_Opcode_Table.put(OP_div, B_OPCODE_div);
-		B_Opcode_Table.put(OP_realdiv, B_OPCODE_realdiv);
-		B_Opcode_Table.put(OP_mod, B_OPCODE_mod);
-		B_Opcode_Table.put(OP_exp, B_OPCODE_exp);
-		B_Opcode_Table.put(OP_uminus, B_OPCODE_uminus);
+		B_Opcodes.put(OP_dotdot, B_OPCODE_dotdot);
+		B_Opcodes.put(OP_plus, B_OPCODE_plus);
+		B_Opcodes.put(OP_minus, B_OPCODE_minus);
+		B_Opcodes.put(OP_times, B_OPCODE_times);
+		B_Opcodes.put(OP_div, B_OPCODE_div);
+		B_Opcodes.put(OP_realdiv, B_OPCODE_realdiv);
+		B_Opcodes.put(OP_mod, B_OPCODE_mod);
+		B_Opcodes.put(OP_exp, B_OPCODE_exp);
+		B_Opcodes.put(OP_uminus, B_OPCODE_uminus);
 
-		B_Opcode_Table.put(OP_lt, B_OPCODE_lt);
-		B_Opcode_Table.put(OP_leq, B_OPCODE_leq);
-		B_Opcode_Table.put(OP_gt, B_OPCODE_gt);
-		B_Opcode_Table.put(OP_geq, B_OPCODE_geq);
-		B_Opcode_Table.put(OP_bool, B_OPCODE_bool);
-		B_Opcode_Table.put(OP_true, B_OPCODE_true);
-		B_Opcode_Table.put(OP_false, B_OPCODE_false);
-		B_Opcode_Table.put(OP_nat, B_OPCODE_nat);
-		B_Opcode_Table.put(OP_int, B_OPCODE_int);
-		B_Opcode_Table.put(OP_real, B_OPCODE_real);
-		B_Opcode_Table.put(OP_string, B_OPCODE_string);
+		B_Opcodes.put(OP_lt, B_OPCODE_lt);
+		B_Opcodes.put(OP_leq, B_OPCODE_leq);
+		B_Opcodes.put(OP_gt, B_OPCODE_gt);
+		B_Opcodes.put(OP_geq, B_OPCODE_geq);
+		B_Opcodes.put(OP_bool, B_OPCODE_bool);
+		B_Opcodes.put(OP_true, B_OPCODE_true);
+		B_Opcodes.put(OP_false, B_OPCODE_false);
+		B_Opcodes.put(OP_nat, B_OPCODE_nat);
+		B_Opcodes.put(OP_int, B_OPCODE_int);
+		B_Opcodes.put(OP_real, B_OPCODE_real);
+		B_Opcodes.put(OP_string, B_OPCODE_string);
 
-		B_Opcode_Table.put(OP_finite, B_OPCODE_finite);
-		B_Opcode_Table.put(OP_card, B_OPCODE_card);
+		B_Opcodes.put(OP_finite, B_OPCODE_finite);
+		B_Opcodes.put(OP_card, B_OPCODE_card);
 
-		B_Opcode_Table.put(OP_len, B_OPCODE_len);
-		B_Opcode_Table.put(OP_append, B_OPCODE_append);
-		B_Opcode_Table.put(OP_seq, B_OPCODE_seq);
-		B_Opcode_Table.put(OP_head, B_OPCODE_head);
-		B_Opcode_Table.put(OP_tail, B_OPCODE_tail);
-		B_Opcode_Table.put(OP_subseq, B_OPCODE_subseq);
-		B_Opcode_Table.put(OP_conc, B_OPCODE_conc);
+		B_Opcodes.put(OP_len, B_OPCODE_len);
+		B_Opcodes.put(OP_append, B_OPCODE_append);
+		B_Opcodes.put(OP_seq, B_OPCODE_seq);
+		B_Opcodes.put(OP_head, B_OPCODE_head);
+		B_Opcodes.put(OP_tail, B_OPCODE_tail);
+		B_Opcodes.put(OP_subseq, B_OPCODE_subseq);
+		B_Opcodes.put(OP_conc, B_OPCODE_conc);
 
-		B_Opcode_Table.put(OP_min, B_OPCODE_min);
-		B_Opcode_Table.put(OP_max, B_OPCODE_max);
-		B_Opcode_Table.put(OP_setprod, B_OPCODE_setprod);
-		B_Opcode_Table.put(OP_setsum, B_OPCODE_setsum);
-		B_Opcode_Table.put(OP_permseq, B_OPCODE_permseq);
+		B_Opcodes.put(OP_min, B_OPCODE_min);
+		B_Opcodes.put(OP_max, B_OPCODE_max);
+		B_Opcodes.put(OP_setprod, B_OPCODE_setprod);
+		B_Opcodes.put(OP_setsum, B_OPCODE_setsum);
+		B_Opcodes.put(OP_permseq, B_OPCODE_permseq);
 
-		B_Opcode_Table.put(OP_pow1, B_OPCODE_pow1);
+		B_Opcodes.put(OP_pow1, B_OPCODE_pow1);
 
 		//relations
-		B_Opcode_Table.put(OP_rel_inverse, B_OPCODE_rel_inverse);
+		B_Opcodes.put(OP_rel_inverse, B_OPCODE_rel_inverse);
 
-		B_Opcode_Table.put(OP_assert, B_OPCODE_assert);
+		B_Opcodes.put(OP_assert, B_OPCODE_assert);
 	}
 
 	public static boolean contains(UniqueString s) {
-		return B_Opcode_Table.containsKey(s);
+		return B_Opcodes.containsKey(s);
 	}
 
 	public static int getOpcode(UniqueString s) {
-		return B_Opcode_Table.get(s);
+		return B_Opcodes.get(s);
 	}
 }
diff --git a/src/main/java/de/tla2b/translation/BDefinitionsFinder.java b/src/main/java/de/tla2b/translation/BDefinitionsFinder.java
index e8a5ddf1d2074e8a297f1ffb800f36299863002b..fcbf6c33ca281a5a01f442d503a282547930f8a5 100644
--- a/src/main/java/de/tla2b/translation/BDefinitionsFinder.java
+++ b/src/main/java/de/tla2b/translation/BDefinitionsFinder.java
@@ -12,7 +12,7 @@ import java.util.HashSet;
 import java.util.Set;
 
 public class BDefinitionsFinder extends AbstractASTVisitor implements ASTConstants, ToolGlobals, TranslationGlobals {
-	private final HashSet<OpDefNode> bDefinitionsSet = new HashSet<>();
+	private final Set<OpDefNode> bDefinitionsSet = new HashSet<>();
 
 	public BDefinitionsFinder(SpecAnalyser specAnalyser) {
 		if (specAnalyser.getConfigFileEvaluator() != null) {
@@ -50,7 +50,7 @@ public class BDefinitionsFinder extends AbstractASTVisitor implements ASTConstan
 			}
 		}
 
-		HashSet<OpDefNode> temp = new HashSet<>(bDefinitionsSet);
+		Set<OpDefNode> temp = new HashSet<>(bDefinitionsSet);
 		for (OpDefNode opDefNode : temp) {
 			visitExprNode(opDefNode.getBody());
 		}