diff --git a/CMakeLists.txt b/CMakeLists.txt
index a7c57bb..45473f6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,6 +7,8 @@ include_directories(src)
 
 add_executable(groundc
         src/main.c
+        src/interpreter.c
+        src/interpreter.h
         src/parser.c
         src/parser.h
         src/lexer.c
diff --git a/src/interpreter.c b/src/interpreter.c
index 289544c..599fa16 100644
--- a/src/interpreter.c
+++ b/src/interpreter.c
@@ -50,13 +50,6 @@ void runtimeError(GroundRuntimeError error, char* what, GroundInstruction* where
     exit(1);
 }
 
-void addLabel(GroundLabel **head, const char *id, int data) {
-    GroundLabel* item = malloc(sizeof(GroundLabel));
-    snprintf(item->id, MAX_ID_LEN, "%s", id);
-    item->lineNum = data;
-    HASH_ADD_STR(*head, id, item);
-}
-
 GroundLabel* findLabel(GroundLabel* head, const char *id) {
     GroundLabel *item;
     HASH_FIND_STR(head, id, item);
@@ -68,10 +61,14 @@ void deleteLabel(GroundLabel** head, GroundLabel *item) {
     free(item);
 }
 
-void addVariable(GroundVariable **head, const char *id, GroundValue data) {
-    GroundVariable* item = malloc(sizeof(GroundVariable));
+void addLabel(GroundLabel **head, const char *id, int data) {
+    GroundLabel* label = findLabel(*head, id);
+    if (label) {
+        deleteLabel(head, label);
+    }
+    GroundLabel* item = malloc(sizeof(GroundLabel));
     snprintf(item->id, MAX_ID_LEN, "%s", id);
-    item->value = data;
+    item->lineNum = data;
     HASH_ADD_STR(*head, id, item);
 }
 
@@ -86,6 +83,17 @@ void deleteVariable(GroundVariable** head, GroundVariable *item) {
     free(item);
 }
 
+void addVariable(GroundVariable **head, const char *id, GroundValue data) {
+    GroundVariable* variable = findVariable(*head, id);
+    if (variable) {
+        deleteVariable(head, variable);
+    }
+    GroundVariable* item = malloc(sizeof(GroundVariable));
+    snprintf(item->id, MAX_ID_LEN, "%s", id);
+    item->value = data;
+    HASH_ADD_STR(*head, id, item);
+}
+
 void interpretGroundProgram(GroundProgram* in) {
     GroundLabel* labels = NULL;
     GroundVariable* variables = NULL;
@@ -100,18 +108,22 @@ void interpretGroundProgram(GroundProgram* in) {
         }
     }
     while (currentInstruction < in->size) {
-        interpretGroundInstruction(&in->instructions[currentInstruction], &scope);
+        interpretGroundInstruction(in->instructions[currentInstruction], &scope);
         currentInstruction++;
     }
     
 }
 
-void interpretGroundInstruction(GroundInstruction* in, GroundScope* scope) {
+void interpretGroundInstruction(GroundInstruction inst, GroundScope* scope) {
+    GroundInstruction copied_inst = copyGroundInstruction(&inst);
+    GroundInstruction* in = &copied_inst;
+
     // Insert variables prefixed with $
     for (int i = 0; i < in->args.length; i++) {
         if (in->args.args[i].type == VALREF) {
-            GroundVariable* variable = findVariable(*scope->variables, in->args.args[0].value.refName);
+            GroundVariable* variable = findVariable(*scope->variables, in->args.args[i].value.refName);
             if (variable) {
+                free(in->args.args[i].value.refName); // Free the strdup'd refName
                 in->args.args[i].value.value = variable->value;
                 in->args.args[i].type = VALUE;
             } else {
@@ -239,7 +251,7 @@ void interpretGroundInstruction(GroundInstruction* in, GroundScope* scope) {
                 if (right->type != STRING) {
                     runtimeError(ARG_TYPE_MISMATCH, "Expecting a String for arg 2", in, currentInstruction);
                 }
-                char* newString = malloc(sizeof(char));
+                char* newString = malloc(strlen(left->data.stringVal) + strlen(right->data.stringVal));
                 strcpy(newString, left->data.stringVal);
                 strcat(newString, right->data.stringVal);
 
@@ -261,7 +273,7 @@ void interpretGroundInstruction(GroundInstruction* in, GroundScope* scope) {
     
                     if (right->type == INT) {
                         result += right->data.intVal;
-                    } else if (left->type == DOUBLE) {
+                    } else if (right->type == DOUBLE) {
                         result += right->data.doubleVal;
                     }
 
@@ -275,9 +287,67 @@ void interpretGroundInstruction(GroundInstruction* in, GroundScope* scope) {
             }
             break;
         }
+        case EQUAL: {
+            if (in->args.length < 3) {
+                runtimeError(TOO_FEW_ARGS, "Expecting 3 args", in, currentInstruction);
+            }
+            if (in->args.length > 3) {
+                runtimeError(TOO_MANY_ARGS, "Expecting 3 args", in, currentInstruction);
+            }
+            if (in->args.args[0].type != VALUE) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a Value for arg 1", in, currentInstruction);
+            }
+            if (in->args.args[1].type != VALUE) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a Value for arg 2", in, currentInstruction);
+            }
+            if (in->args.args[2].type != DIRREF) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a DirectRef for arg 3", in, currentInstruction);
+            }
+
+            GroundValue* left = &in->args.args[0].value.value;
+            GroundValue* right = &in->args.args[1].value.value;
+
+            if (left->type != right->type) {
+                addVariable(scope->variables, in->args.args[2].value.refName, createBoolGroundValue(false));
+            } else {
+                switch (left->type) {
+                    case INT: {
+                        bool cond = (left->data.intVal == right->data.intVal);
+                        addVariable(scope->variables, in->args.args[2].value.refName, createBoolGroundValue(cond));
+                        break;
+                    }
+                    case DOUBLE: {
+                        bool cond = (left->data.doubleVal == right->data.doubleVal);
+                        addVariable(scope->variables, in->args.args[2].value.refName, createBoolGroundValue(cond));
+                        break;
+                    }
+                    case STRING: {
+                        bool cond = (strcmp(left->data.stringVal, right->data.stringVal) == 0);
+                        addVariable(scope->variables, in->args.args[2].value.refName, createBoolGroundValue(cond));
+                        break;
+                    }
+                    case CHAR: {
+                        bool cond = (left->data.charVal == right->data.charVal);
+                        addVariable(scope->variables, in->args.args[2].value.refName, createBoolGroundValue(cond));
+                        break;
+                    }
+                    case BOOL: {
+                        bool cond = (left->data.boolVal == right->data.boolVal);
+                        addVariable(scope->variables, in->args.args[2].value.refName, createBoolGroundValue(cond));
+                        break;
+                    }
+                    default: {
+                        addVariable(scope->variables, in->args.args[2].value.refName, createBoolGroundValue(false));
+                        break;
+                    }
+                }
+            }
+            break;
+        }
         default: {
             runtimeError(FIXME, "Currently unimplemented instruction", in, currentInstruction);
         }
     }
 
+    freeGroundInstruction(in);
 }
diff --git a/src/interpreter.h b/src/interpreter.h
index 06c677f..24e242a 100644
--- a/src/interpreter.h
+++ b/src/interpreter.h
@@ -28,5 +28,7 @@ typedef struct GroundScope {
 } GroundScope;
 
 void interpretGroundProgram(GroundProgram* in);
-void interpretGroundInstruction(GroundInstruction* in, GroundScope* scope);
+void interpretGroundInstruction(GroundInstruction inst, GroundScope* scope);
+
+
 #endif
diff --git a/src/types.c b/src/types.c
index 169e869..07d0987 100644
--- a/src/types.c
+++ b/src/types.c
@@ -142,8 +142,33 @@ void freeGroundInstruction(GroundInstruction* gi) {
     for (size_t i = 0; i < gi-> args.length; i++) {
         freeGroundArg(&gi->args.args[i]);
     }
+    free(gi->args.args);
 }
 
+GroundInstruction copyGroundInstruction(const GroundInstruction* inst) {
+    GroundInstruction newInst;
+    newInst.type = inst->type;
+    newInst.args.length = inst->args.length;
+    if (inst->args.length > 0) {
+        newInst.args.args = malloc(inst->args.length * sizeof(GroundArg));
+        for (size_t i = 0; i < inst->args.length; i++) {
+            newInst.args.args[i].type = inst->args.args[i].type;
+            if (inst->args.args[i].type == VALUE) {
+                newInst.args.args[i].value.value = inst->args.args[i].value.value;
+                if (inst->args.args[i].value.value.type == STRING) {
+                    newInst.args.args[i].value.value.data.stringVal = strdup(inst->args.args[i].value.value.data.stringVal);
+                }
+            } else {
+                newInst.args.args[i].value.refName = strdup(inst->args.args[i].value.refName);
+            }
+        }
+    } else {
+        newInst.args.args = NULL;
+    }
+    return newInst;
+}
+
+
 void addArgToInstruction(GroundInstruction* gi, GroundArg arg) {
     gi->args.length ++;
     GroundArg* newArgs = realloc(gi->args.args, gi->args.length * sizeof(GroundArg));
diff --git a/src/types.h b/src/types.h
index c980fc2..6bfbad3 100644
--- a/src/types.h
+++ b/src/types.h
@@ -116,6 +116,9 @@ GroundInstruction createGroundInstruction(GroundInstType type);
 // Frees all data stored on the heap in a GroundInstruction.
 void freeGroundInstruction(GroundInstruction* gi);
 
+// Creates a deep copy of a GroundInstruction.
+GroundInstruction copyGroundInstruction(const GroundInstruction* gi);
+
 // Adds arg (arg) to the GroundInstruction (gi).
 void addArgToInstruction(GroundInstruction* gi, GroundArg arg);
 
diff --git a/tests/to1000.grnd b/tests/to1000.grnd
new file mode 100644
index 0000000..96e4e95
--- /dev/null
+++ b/tests/to1000.grnd
@@ -0,0 +1,9 @@
+set &var 0
+println "dingle"
+@jump
+add 1 $var &var
+println $var
+equal $var 1000000 &cond
+if $cond %end
+jump %jump
+@end