diff --git a/include/parse.hpp b/include/parse.hpp
index bd292bd..fc3b29f 100644
--- a/include/parse.hpp
+++ b/include/parse.hpp
@@ -37,10 +37,10 @@ std::pair<list*, uint32_t> parse_list_until(const char* in, uint32_t size, uint3
 std::pair<list*, uint32_t> parse_list_until(const char* in, uint32_t size, uint32_t start, std::string const& end_word);
 std::tuple<list*, uint32_t, std::string> parse_list_until(const char* in, uint32_t size, uint32_t start, std::vector<std::string> const& end_words, const char* expecting=NULL);
 // name
-std::pair<std::string, uint32_t> parse_varname(const char* in, uint32_t size, uint32_t start);
+std::pair<std::string, uint32_t> parse_varname(const char* in, uint32_t size, uint32_t start, bool specialvars=true);
 
 // subarg parsers
-std::pair<arithmetic_subarg*, uint32_t> parse_arithmetic(const char* in, uint32_t size, uint32_t start);
+std::pair<arithmetic*, uint32_t> parse_arithmetic(const char* in, uint32_t size, uint32_t start);
 std::pair<manipulation_subarg*, uint32_t> parse_manipulation(const char* in, uint32_t size, uint32_t start);
 // arg parser
 std::pair<arg*, uint32_t> parse_arg(const char* in, uint32_t size, uint32_t start, const char* end=ARG_END, const char* unexpected=SPECIAL_TOKENS, bool doquote=true);
diff --git a/include/recursive.hpp b/include/recursive.hpp
index 50912b5..a76139a 100644
--- a/include/recursive.hpp
+++ b/include/recursive.hpp
@@ -205,6 +205,31 @@ void recurse(bool (&fct)(_obj*, Args...), _obj* o, Args... args)
       recurse(fct, t->sbsh, args...);
       break;
     }
+    case _obj::subarg_arithmetic :
+    {
+      arithmetic_subarg* t = dynamic_cast<arithmetic_subarg*>(o);
+      recurse(fct, t->arith, args...);
+      break;
+    }
+    case _obj::arithmetic_subshell :
+    {
+      subshell_arithmetic* t = dynamic_cast<subshell_arithmetic*>(o);
+      recurse(fct, t->sbsh, args...);
+      break;
+    }
+    case _obj::arithmetic_operation :
+    {
+      operation_arithmetic* t = dynamic_cast<operation_arithmetic*>(o);
+      recurse(fct, t->val1, args...);
+      recurse(fct, t->val2, args...);
+      break;
+    }
+    case _obj::arithmetic_parenthesis :
+    {
+      parenthesis_arithmetic* t = dynamic_cast<parenthesis_arithmetic*>(o);
+      recurse(fct, t->val, args...);
+      break;
+    }
 
     default: break; //do nothing
   }
diff --git a/include/struc.hpp b/include/struc.hpp
index 97bce64..2e7b761 100644
--- a/include/struc.hpp
+++ b/include/struc.hpp
@@ -90,6 +90,7 @@ public:
     _pipeline,
     _condlist,
     _list,
+    arithmetic_operation, arithmetic_number, arithmetic_variable, arithmetic_parenthesis, arithmetic_subshell,
     block_subshell, block_brace, block_main, block_cmd, block_function, block_case, block_if, block_for, block_while, block_until };
   _objtype type;
 
@@ -97,6 +98,13 @@ public:
   virtual std::string generate(int ind)=0;
 };
 
+// meta arithmetic type
+class arithmetic : public _obj
+{
+public:
+  virtual std::string generate(int ind)=0;
+};
+
 // meta subarg type
 class subarg : public _obj
 {
@@ -458,12 +466,14 @@ public:
 class arithmetic_subarg : public subarg
 {
 public:
-  arithmetic_subarg() { type=_obj::subarg_arithmetic; }
-  ~arithmetic_subarg() {;}
+  arithmetic_subarg(arithmetic* a=nullptr) { type=_obj::subarg_arithmetic; arith=a; }
+  ~arithmetic_subarg() {
+    if(arith!=nullptr) delete arith;
+  }
 
-  std::string val;
+  arithmetic* arith;
 
-  std::string generate(int ind) { return "$(("+val+"))"; }
+  std::string generate(int ind);
 };
 
 class subshell_subarg : public subarg
@@ -503,5 +513,67 @@ public:
   std::string generate(int ind);
 };
 
+// Arithmetic subtypes //
+
+class operation_arithmetic : public arithmetic
+{
+public:
+  operation_arithmetic(std::string op="", arithmetic* a=nullptr, arithmetic* b=nullptr, bool pre=false) { type=_obj::arithmetic_operation; oper=op; val1=a; val2=b; precedence=pre; }
+  ~operation_arithmetic() {
+    if(val1 != nullptr) delete val1;
+    if(val2 != nullptr) delete val2;
+  }
+
+  std::string oper;
+  bool precedence;
+  arithmetic *val1, *val2;
+  std::string generate(int ind);
+};
+
+class subshell_arithmetic : public arithmetic
+{
+public:
+  subshell_arithmetic(subshell* a=nullptr) { type=_obj::arithmetic_subshell; sbsh=a; }
+  ~subshell_arithmetic() {
+    if(sbsh!=nullptr) delete sbsh;
+  }
+
+  subshell* sbsh;
+
+  std::string generate(int ind);
+};
+
+class parenthesis_arithmetic : public arithmetic
+{
+public:
+  parenthesis_arithmetic(arithmetic* a=nullptr) { type=_obj::arithmetic_parenthesis; val=a; }
+  ~parenthesis_arithmetic() {
+    if(val!=nullptr) delete val;
+  }
+
+  arithmetic* val;
+
+  std::string generate(int ind);
+};
+
+class number_arithmetic : public arithmetic
+{
+public:
+  number_arithmetic(std::string const& a) { type=_obj::arithmetic_number; val=a; }
+
+  std::string val;
+
+  std::string generate(int ind) { return val; }
+};
+
+class variable_arithmetic : public arithmetic
+{
+public:
+  variable_arithmetic(std::string const& in) { type=_obj::arithmetic_variable; varname=in; }
+
+  std::string varname;
+
+  std::string generate(int ind) { return varname; }
+};
 
 #endif //STRUC_HPP
diff --git a/include/util.hpp b/include/util.hpp
index ec570e3..28e53c2 100644
--- a/include/util.hpp
+++ b/include/util.hpp
@@ -23,6 +23,8 @@ std::string dirname(std::string const& in);
 
 std::string indent(int n);
 
+bool is_among(std::string const& in, std::vector<std::string> const& values);
+
 std::vector<std::string> split(std::string const& in, const char* splitters);
 std::vector<std::string> split(std::string const& in, char c);
 
diff --git a/src/debashify.cpp b/src/debashify.cpp
index 9182166..a837ca3 100644
--- a/src/debashify.cpp
+++ b/src/debashify.cpp
@@ -96,22 +96,11 @@ bool debashify_extended_redirects(pipeline* in)
 
 // replace <() and >()
 /*
- <() replacer:
-REPLACE: CMD <(PSUB)
-TO:
+REPLACE TO:
   fifoN=${TMPDIR-/tmp}/lxshfifo_$(__lxsh_random 10)
   mkfifo "$fifoN"
-  ( {PSUB;} > "$fifoN" ; rm "$fifoN") &
+  ( {PSUB;} [>|<] "$fifoN" ; rm "$fifoN") &
   CMD "$fifoN"
-
-REPLACE CMD >(PSUB)
-TO:
-  fifoN=${TMPDIR-/tmp}/lxshfifo_$(__lxsh_random 10)
-  mkfifo "$fifoN"
-  ( {PSUB;} < "$fifoN" ; rm "$fifoN") &
-  jobN
-  CMD "$fifoN"
-  wait "$jobN"
 */
 bool debashify_procsub(list* lst)
 {
diff --git a/src/generate.cpp b/src/generate.cpp
index aff450b..7ea9416 100644
--- a/src/generate.cpp
+++ b/src/generate.cpp
@@ -363,6 +363,55 @@ std::string procsub_subarg::generate(int ind)
     return '<' + sbsh->generate(ind);
 }
 
+std::string arithmetic_subarg::generate(int ind)
+{
+  std::string ret;
+  ret += "$((";
+  if(!opt_minimize) ret += ' ';
+  ret += arith->generate(ind);
+  if(!opt_minimize) ret += ' ';
+  ret += "))";
+  return ret;
+}
+
+// ARITHMETIC
+
+std::string operation_arithmetic::generate(int ind)
+{
+  std::string ret;
+  if(precedence)
+  {
+    ret += oper;
+    if(!opt_minimize) ret += ' ';
+    ret += val1->generate(ind);
+  }
+  else
+  {
+    ret += val1->generate(ind);
+    if(!opt_minimize) ret += ' ';
+    ret += oper;
+    if(!opt_minimize) ret += ' ';
+    ret += val2->generate(ind);
+  }
+  return ret;
+}
+
+std::string parenthesis_arithmetic::generate(int ind)
+{
+  std::string ret;
+  ret += '(';
+  if(!opt_minimize) ret += ' ';
+  ret += val->generate(ind);
+  if(!opt_minimize) ret += ' ';
+  ret += ')';
+  return ret;
+}
+
+std::string subshell_arithmetic::generate(int ind)
+{
+  return '$' + sbsh->generate(ind);
+}
+
 // TEMPLATE
 
 // std::string thing::generate(int ind)
diff --git a/src/minimize.cpp b/src/minimize.cpp
index 9ec348c..2c064c0 100644
--- a/src/minimize.cpp
+++ b/src/minimize.cpp
@@ -56,6 +56,12 @@ bool r_replace_var(_obj* in, strmap_t* varmap)
 {
   switch(in->type)
   {
+    case _obj::arithmetic_variable: {
+      variable_arithmetic* t = dynamic_cast<variable_arithmetic*>(in);
+      auto el=varmap->find(t->varname);
+      if(el!=varmap->end())
+        t->varname = el->second;
+    }; break;
     case _obj::subarg_variable: {
       variable_subarg* t = dynamic_cast<variable_subarg*>(in);
       auto el=varmap->find(t->varname);
diff --git a/src/parse.cpp b/src/parse.cpp
index 4f301f8..731642a 100644
--- a/src/parse.cpp
+++ b/src/parse.cpp
@@ -18,6 +18,8 @@ bool g_bash=false;
 #define PARSE_ERROR(str, i) ztd::format_error(str, "", in, i)
 
 // constants
+const std::vector<std::string> arithmetic_precedence_operators = { "!", "~", "+", "-" };
+const std::vector<std::string> arithmetic_operators = { "+", "-", "*", "/", "=", "==", "!=", "&", "|", "^", "<<", ">>", "&&", "||" };
 
 const std::vector<std::string> all_reserved_words = { "if", "then", "else", "fi", "case", "esac", "for", "while", "do", "done", "{", "}" };
 const std::vector<std::string> out_reserved_words = { "then", "else", "fi", "esac", "do", "done", "}" };
@@ -125,13 +127,13 @@ uint32_t skip_unread(const char* in, uint32_t size, uint32_t start)
 
 // parse fcts
 
-std::pair<std::string, uint32_t> parse_varname(const char* in, uint32_t size, uint32_t start)
+std::pair<std::string, uint32_t> parse_varname(const char* in, uint32_t size, uint32_t start, bool specialvars)
 {
   uint32_t i=start;
   std::string ret;
 
   // special vars
-  if(is_in(in[i], SPECIAL_VARS) || (in[i]>='0' && in[i]<='1'))
+  if(specialvars && (is_in(in[i], SPECIAL_VARS) || (in[i]>='0' && in[i]<='1')) )
   {
     ret=in[i];
     i++;
@@ -146,28 +148,97 @@ std::pair<std::string, uint32_t> parse_varname(const char* in, uint32_t size, ui
   return std::make_pair(ret, i);
 }
 
+std::pair<std::string, uint32_t> get_operator(const char* in, uint32_t size, uint32_t start)
+{
+  uint32_t i=start;
+  std::string ret;
+
+  while(!is_alphanum(in[i]) && !is_in(in[i], SEPARATORS) && in[i]!=')' )
+    i++;
+
+  ret = std::string(in+start, i-start);
+
+  return std::make_pair(ret, i);
+}
+
 // parse an arithmetic
 // ends at ))
-// for now, uses subshell parsing then takes raw string value
 // temporary, to improve
-std::pair<arithmetic_subarg*, uint32_t> parse_arithmetic(const char* in, uint32_t size, uint32_t start)
+std::pair<arithmetic*, uint32_t> parse_arithmetic(const char* in, uint32_t size, uint32_t start)
 {
-  arithmetic_subarg* ret = new arithmetic_subarg;
+  arithmetic* ret = nullptr;
   uint32_t i=start;
 
 #ifndef NO_PARSE_CATCH
   try
   {
 #endif
-    auto pp=parse_subshell(in, size, i);
-    i=pp.second;
-    delete pp.first;
-    if(i >= size || in[i]!=')')
+    i = skip_chars(in, size, i, SEPARATORS);
+    if(i>size || in[i] == ')')
+      throw PARSE_ERROR( "Unexpected end of arithmetic", i );
+
+    auto po = get_operator(in, size, i);
+    if(is_among(po.first, arithmetic_precedence_operators))
     {
-      throw PARSE_ERROR( "Unexpected token ')', expecting '))'", i );
+      auto pa = parse_arithmetic(in, size, po.second);
+      ret = new operation_arithmetic(po.first, pa.first, nullptr, true);
+      i=pa.second;
+    }
+    else
+    {
+      if(in[i]=='-' || is_num(in[i]))
+      {
+        uint32_t j=i;
+        if(in[i]=='-')
+          i++;
+        while(is_num(in[i]))
+          i++;
+        ret = new number_arithmetic( std::string(in+j, i-j) );
+      }
+      else if(word_eq("$(", in, size, i))
+      {
+        auto ps = parse_subshell(in, size, i+2);
+        ret = new subshell_arithmetic(ps.first);
+        i=ps.second;
+      }
+      else if(in[i] == '(')
+      {
+        auto pa = parse_arithmetic(in, size, i+1);
+        ret = pa.first;
+        i = pa.second+1;
+      }
+      else
+      {
+        bool specialvars=false;
+        if(in[i] == '$')
+        {
+          specialvars=true;
+          i++;
+        }
+        auto pp = parse_varname(in, size, i, specialvars);
+        ret = new variable_arithmetic(pp.first);
+        i=pp.second;
+      }
+
+      i = skip_chars(in, size, i, SEPARATORS);
+      auto po = get_operator(in, size, i);
+      if(po.first != "")
+      {
+        if(!is_among(po.first, arithmetic_operators))
+          throw PARSE_ERROR( "Unknown arithmetic operator: "+po.first, i);
+        arithmetic* val1 = ret;
+        auto pa = parse_arithmetic(in, size, po.second);
+        arithmetic* val2 = pa.first;
+        i = pa.second;
+        ret = new operation_arithmetic(po.first, val1, val2);
+        i = skip_chars(in, size, i, SEPARATORS);
+      }
+
+      if(i >= size)
+        throw PARSE_ERROR( "Unexpected end of file, expecting '))'", i );
+      if(in[i] != ')')
+        throw PARSE_ERROR( "Unexpected token, expecting ')'", i);
     }
-    ret->val = std::string(in+start, i-start-1);
-    i++;
 #ifndef NO_PARSE_CATCH
   }
   catch(ztd::format_error& e)
@@ -252,9 +323,14 @@ std::pair<arg*, uint32_t> parse_arg(const char* in, uint32_t size, uint32_t star
               ret->add(new string_subarg(tmpstr));
             // get arithmetic
             auto r=parse_arithmetic(in, size, i+3);
-            r.first->quoted=true;
-            ret->add(r.first);
-            j = i = r.second;
+            arithmetic_subarg* tt = new arithmetic_subarg(r.first);
+            tt->quoted=true;
+            ret->add(tt);
+            i = r.second;
+            if(!word_eq("))", in, size, i))
+              throw PARSE_ERROR( "Unexpected token ')', expecting '))'", i);
+            i+=2;
+            j=i;
           }
           else if( word_eq("$(", in, size, i) ) // substitution
           {
@@ -321,8 +397,12 @@ std::pair<arg*, uint32_t> parse_arg(const char* in, uint32_t size, uint32_t star
           ret->add(new string_subarg(tmpstr));
         // get arithmetic
         auto r=parse_arithmetic(in, size, i+3);
-        ret->add(r.first);
-        j = i = r.second;
+        ret->add(new arithmetic_subarg(r.first));
+        i = r.second;
+        if(!word_eq("))", in, size, i))
+          throw PARSE_ERROR( "Unexpected token ')', expecting '))'", i);
+        i+=2;
+        j=i;
       }
       else if( word_eq("$(", in, size, i) ) // substitution
       {
diff --git a/src/processing.cpp b/src/processing.cpp
index cfd0e8b..dc244bf 100644
--- a/src/processing.cpp
+++ b/src/processing.cpp
@@ -268,6 +268,11 @@ bool r_get_var(_obj* in, countmap_t* defmap, countmap_t* callmap)
       if(!callmap->insert( std::make_pair(t->varname, 1) ).second)
         (*callmap)[t->varname]++;
     }; break;
+    case _obj::arithmetic_variable: {
+      variable_arithmetic* t = dynamic_cast<variable_arithmetic*>(in);
+      if(!callmap->insert( std::make_pair(t->varname, 1) ).second)
+        (*callmap)[t->varname]++;
+    }; break;
     case _obj::subarg_manipulation: {
       manipulation_subarg* t = dynamic_cast<manipulation_subarg*>(in);
       if(!callmap->insert( std::make_pair(t->varname, 1) ).second)
diff --git a/src/util.cpp b/src/util.cpp
index eedc38d..e0bc7ff 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -38,6 +38,14 @@ std::string dirname(std::string const& in)
     return ".";
 }
 
+bool is_among(std::string const& in, std::vector<std::string> const& values)
+{
+  for(auto it: values)
+    if(in == it)
+      return true;
+  return false;
+}
+
 std::vector<std::string> split(std::string const& in, const char* splitters)
 {
   uint32_t i=0,j=0;