diff --git a/lang/m2/libm2/CSP.mod b/lang/m2/libm2/CSP.mod
index 41644603..b1bb3290 100644
--- a/lang/m2/libm2/CSP.mod
+++ b/lang/m2/libm2/CSP.mod
@@ -147,7 +147,7 @@ IMPLEMENTATION MODULE CSP;
 
   PROCEDURE COEND;
   (* End of a COBEGIN .. COEND structure *)
-    VAR	aux: ProcessType;
+    (* VAR	aux: ProcessType; *)
   BEGIN
 	IF cp^.sons > 0 THEN
 		DoTransfer
@@ -219,7 +219,7 @@ IMPLEMENTATION MODULE CSP;
   PROCEDURE Send(data: ARRAY OF BYTE; VAR ch: Channel);
   (* Send a message with the data to the cvhannel ch *)
     VAR	m: ByteAddress;
-	aux: ProcessType;
+	(* aux: ProcessType; *)
 	i: CARDINAL;
   BEGIN
 	WITH ch^ DO
@@ -295,7 +295,7 @@ IMPLEMENTATION MODULE CSP;
   PROCEDURE GUARD(cond: BOOLEAN; ch: Channel;
 		  VAR dest: ARRAY OF BYTE): BOOLEAN;
   (* Evaluates a guard, including reception management *)
-    VAR	aux: ProcessType;
+    (* VAR	aux: ProcessType; *)
   BEGIN
 	IF NOT cond THEN
 		RETURN FALSE
diff --git a/lang/m2/libm2/InOut.mod b/lang/m2/libm2/InOut.mod
index 50b69ed5..eb6799fa 100644
--- a/lang/m2/libm2/InOut.mod
+++ b/lang/m2/libm2/InOut.mod
@@ -183,7 +183,6 @@ IMPLEMENTATION MODULE InOut ;
 		       VAR buf : ARRAY OF CHAR);
   VAR	i : INTEGER;
 	j : CARDINAL;
-	ch: CHAR;
   BEGIN
 	Done := TRUE;
 	IF isatty(0) THEN
diff --git a/lang/m2/libm2/MathLib0.mod b/lang/m2/libm2/MathLib0.mod
index 9caf5b19..9834ac03 100644
--- a/lang/m2/libm2/MathLib0.mod
+++ b/lang/m2/libm2/MathLib0.mod
@@ -34,9 +34,11 @@ BEGIN
 END exp;
 
 PROCEDURE entier(x: REAL): INTEGER;
+  VAR i: INTEGER;
 BEGIN
 	IF x < 0.0 THEN
-		RETURN - TRUNC(-x);
+		i := TRUNC(-x);
+		RETURN -i;
 	END;
 	RETURN TRUNC(x);
 END entier;
diff --git a/lang/m2/libm2/RealInOut.mod b/lang/m2/libm2/RealInOut.mod
index 430678a6..64a97d24 100644
--- a/lang/m2/libm2/RealInOut.mod
+++ b/lang/m2/libm2/RealInOut.mod
@@ -17,7 +17,7 @@ IMPLEMENTATION MODULE RealInOut;
   BEGIN
 	IF ndigits > MAXWIDTH THEN ndigits := MAXWIDTH; END;
 	IF ndigits < 10 THEN ndigits := 10; END;
-	RealConversions.RealToString(arg, ndigits, -(ndigits - 7), buf, ok);
+	RealConversions.RealToString(arg, ndigits, -INTEGER(ndigits - 7), buf, ok);
 	InOut.WriteString(buf);
   END WriteReal;
 
diff --git a/lang/m2/libm2/Strings.mod b/lang/m2/libm2/Strings.mod
index 5639a7f6..9d122613 100644
--- a/lang/m2/libm2/Strings.mod
+++ b/lang/m2/libm2/Strings.mod
@@ -53,7 +53,6 @@ PROCEDURE Delete(VAR str: ARRAY OF CHAR; inx, len: CARDINAL);
    string are deleted.
 *)
 VAR	length: CARDINAL;
-	i : CARDINAL;
 BEGIN
 	IF len = 0 THEN RETURN; END;
 	length := Length(str);