public String toString() {
		StringBuilder sb = new StringBuilder();
		sb.append("{\n");
		for(Variable i : vals) {
			sb.append(i.getName());
			sb.append(" : ");
			
			if(i.getType().isPrimitive()) {
				sb.append(i.getType());
			} else if(i.getType().isArray()) {
				sb.append(i.getType());
			} else if(i.getType() == VariableType.PROCEDURE) {
				sb.append("PROCEDURE(");
				for(VariableType j : i.getArg()) {
					sb.append(j);
					sb.append(", ");
				}
				sb.append(")");
			}
			sb.append('\n');
		}
		sb.append("}\n");
		if(nextEnv != null) sb.append(nextEnv.toString());
		return sb.toString();
	}