diff --git a/src/olm.cpp b/src/olm.cpp
index 04a083c36d26f7b0c09682af6e8aae11f8467252..a0d9926d4728600920bc89681d775e58363ab09c 100644
--- a/src/olm.cpp
+++ b/src/olm.cpp
@@ -8,9 +8,6 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <iostream>
-
-#include <string>
-#include <vector>
 #include <algorithm>
 using namespace std;
 
diff --git a/src/opr.cpp b/src/opr.cpp
index 0d9957faa4c7b4240a495d324f0c7a9f0ab81a0f..0604b730151d4a1fe9c15e7d24f7c1f57bbc06b7 100644
--- a/src/opr.cpp
+++ b/src/opr.cpp
@@ -7,8 +7,6 @@
 
 #include <math.h>
 #include <stdlib.h>
-#include <string>
-#include <vector>
 using namespace std;
 
 #include "mystd.h"
diff --git a/src/r-temp.cpp b/src/r-temp.cpp
index 36a88b225a78f4471921d99915cda34ec0e8774e..f87534bf06cadffd8d48e33b1aea71f497ffe650 100644
--- a/src/r-temp.cpp
+++ b/src/r-temp.cpp
@@ -1,8 +1,6 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include <string>
-#include <vector>
 #include <algorithm>
 
 #include "mystd.h"
diff --git a/src/rssm.cpp b/src/rssm.cpp
index ac14ff54f919f561c1bfce1d150d69841ddb596e..b046d30f25241da0824c6eb1ac3a5e8e3daa1552 100644
--- a/src/rssm.cpp
+++ b/src/rssm.cpp
@@ -9,8 +9,6 @@
 #include <stdio.h>
 #include <time.h>
 
-#include <string>
-#include <vector>
 #include <algorithm>
 
 #include <libxml/xmlmemory.h>
diff --git a/src/scan.cpp b/src/scan.cpp
index a1fcfb94a2018e0305d95dd0a98159adc3d686b0..a319b0ead993d2e281c9892f2dcd042f45c7f04c 100644
--- a/src/scan.cpp
+++ b/src/scan.cpp
@@ -10,8 +10,6 @@
 #include <string.h>
 #include <math.h>
 #include <iostream>
-#include <string>
-#include <vector>
 
 #include "mystd.h"
 #include "range.h"
diff --git a/src/xax.l b/src/xax.l
index 7597911b99a950f10fc4c7fce843577c29b7049b..ea476bdd7fa6b2bcbb266efcbb1c40fa69f00f95 100644
--- a/src/xax.l
+++ b/src/xax.l
@@ -64,7 +64,6 @@ e {
 "mod" { return BOP_MOD; } /* man 3 fmod */
 "div" { return BOP_DIV; } /* integer division */
 "over" { return BOP_OVER; } /* binomial coefficient: n over k */
-"in"  { return BOP_IN; }
 
 {ID}	{
         // printf( "lex: An identifier: %s\n", xaxtext );
diff --git a/src/xax.y b/src/xax.y
index d0ea5ca6ab42489417e072d5271a2efabfc3c88d..f9b7b77367ef15460f660e1ba660b1f635034908 100644
--- a/src/xax.y
+++ b/src/xax.y
@@ -9,7 +9,7 @@ using namespace std;
 #include <string.h>
 #include <stdlib.h>
 #include <string>
-#include <vector>
+#include <vector> // for expr.h
 #include "coord.h"
 #include "func.h"
 #include "expr.h"
@@ -23,7 +23,6 @@ double  val;
 void*   ptr;
 CTree*  tree;
 CRef*   ref;
-vector<CTree*>* vtree;
 }
 
 %pure-parser
@@ -38,11 +37,10 @@ int xaxlex(YYSTYPE *xaxlval); /* created by lex.l */
 
 /* tokens created by lex.l: */
 %token <val>  NUM 
-%token <ptr>  REF ARG FRF FNCT END BOP_EQ BOP_NE BOP_GT BOP_GE BOP_LT BOP_LE BOP_AND BOP_OR BOP_XOR BOP_OVER BOP_IN
+%token <ptr>  REF ARG FRF FNCT END BOP_EQ BOP_NE BOP_GT BOP_GE BOP_LT BOP_LE BOP_AND BOP_OR BOP_XOR BOP_OVER
 
 /* tokens created here: */
 %type  <tree>  exp rex
-%type  <vtree> arr list
 %type  <ref>   iva ifu /* {indexed} variable|function  */
 
 /* Operator precedence */
@@ -98,23 +96,12 @@ exp:                       /* double-valued expression */
       | exp BOP_MOD exp    { $$ = new CTree(NFunctions::find("mod"), $1, $3); }
       | exp BOP_DIV exp    { $$ = new CTree(NFunctions::find("idiv"),$1, $3); }
       | exp BOP_OVER exp   { $$ = new CTree(NFunctions::find("over"),$1, $3); }
-      | exp BOP_IN arr     { $$ = new CTree(NFunctions::find("in"),  $1, $3); }
       | '!' exp            { $$ = new CTree(NFunctions::find("!"), $2); }
       | exp '?' exp ':' exp { $$ = new CTree(NFunctions::find("?:"), 
                                              $1, $3, $5); }
       | '(' exp ')'        { $$ = $2; } 
 ;
 
-arr:
-      '[' list ']'         { $$ = $2; }
-;
-
-list:
-        exp                { $$ = new vector<CTree*>; $$->push_back($1); }
-      | list ',' exp       { $$ = $1; $$->push_back($3); }
-;
-
-
 iva:                       /* indexed variable */
         REF                { $$ = new CRef(string((const char*)$1)); }
       | REF '[' rex ']'    { $$ = new CRef(string((const char*)$1), $3); }