diff --git a/src/pp/iloc/model/Instr.java b/src/pp/iloc/model/Instr.java
index 9c39d69..a3fcfaa 100644
--- a/src/pp/iloc/model/Instr.java
+++ b/src/pp/iloc/model/Instr.java
@@ -34,7 +34,7 @@ public abstract class Instr implements Iterable<Op> {
 
 	/** Sets the line number of this instruction. */
 	void setLine(int line) {
-		assert this.line < 0 && line >= 0;
+		assert line >= 0;
 		this.line = line;
 	}
 
@@ -70,7 +70,7 @@ public abstract class Instr implements Iterable<Op> {
 	/** Sets the program in which this instruction occurs.
 	 */
 	void setProgram(Program prog) {
-		assert this.prog == null & prog != null;
+		assert prog != null;
 		this.prog = prog;
 	}
 
diff --git a/src/pp/iloc/model/Op.java b/src/pp/iloc/model/Op.java
index 90397e1..db678ed 100644
--- a/src/pp/iloc/model/Op.java
+++ b/src/pp/iloc/model/Op.java
@@ -142,7 +142,7 @@ public class Op extends Instr {
 		if (getClaz() == COMMENT) {
 			result.append(toCommentString());
 		}
-		if (getOpCode() == OpCode.out) {
+		else if (getOpCode() == OpCode.out) {
 			int size = sourceSize + targetSize + arrowSize;
 			result.append(String.format("%-8s", getOpCode().name()));
 			result.append(String.format("%-" + size + "s ", toSourceString()));