public final GalaxyXPreprocessorParser.expression_return expression() throws RecognitionException {
        GalaxyXPreprocessorParser.expression_return retval = new GalaxyXPreprocessorParser.expression_return();
        retval.start = input.LT(1);
        int expression_StartIndex = input.index();
        Object root_0 = null;

        GalaxyXPreprocessorParser.logical_or_expression_return logical_or_expression103 = null;



        try {
            if ( state.backtracking>0 && alreadyParsedRule(input, 17) ) { return retval; }
            // C:\\Users\\Timo\\EclipseProjects\\GalaxyX\\build\\classes\\com\\galaxyx\\parser\\GalaxyXPreprocessorParser.g:130:2: ( logical_or_expression )
            // C:\\Users\\Timo\\EclipseProjects\\GalaxyX\\build\\classes\\com\\galaxyx\\parser\\GalaxyXPreprocessorParser.g:130:4: logical_or_expression
            {
            root_0 = (Object)adaptor.nil();

            pushFollow(FOLLOW_logical_or_expression_in_expression638);
            logical_or_expression103=logical_or_expression();

            state._fsp--;
            if (state.failed) return retval;
            if ( state.backtracking==0 ) adaptor.addChild(root_0, logical_or_expression103.getTree());

            }

            retval.stop = input.LT(-1);

            if ( state.backtracking==0 ) {

            retval.tree = (Object)adaptor.rulePostProcessing(root_0);
            adaptor.setTokenBoundaries(retval.tree, retval.start, retval.stop);
            }
        }
        catch (RecognitionException re) {
            reportError(re);
            recover(input,re);
    	retval.tree = (Object)adaptor.errorNode(input, retval.start, input.LT(-1), re);

        }
        finally {
            if ( state.backtracking>0 ) { memoize(input, 17, expression_StartIndex); }
        }
        return retval;
    }