diff --git a/VERSION b/VERSION
index 8bdc741eb..5e8c49cd5 100644
--- a/VERSION
+++ b/VERSION
@@ -1,4 +1,4 @@
-3.12.0+dev10 (2009-12-01)
+3.12.0+dev11 (2009-12-01)
 
 # The version string is the first line of this file.
 # It must be in the format described in stdlib/sys.mli
diff --git a/boot/ocamlc b/boot/ocamlc
index e1d00d661..18002552f 100755
Binary files a/boot/ocamlc and b/boot/ocamlc differ
diff --git a/boot/ocamldep b/boot/ocamldep
index eaf01b977..572eea704 100755
Binary files a/boot/ocamldep and b/boot/ocamldep differ
diff --git a/boot/ocamllex b/boot/ocamllex
index d5b63b1c7..0bb44ed19 100755
Binary files a/boot/ocamllex and b/boot/ocamllex differ
diff --git a/parsing/lexer.mll b/parsing/lexer.mll
index 0696aac80..019b23c3d 100644
--- a/parsing/lexer.mll
+++ b/parsing/lexer.mll
@@ -250,7 +250,8 @@ rule token = parse
       { token lexbuf }
   | "_"
       { UNDERSCORE }
-  | "~"  { TILDE }
+  | "~"
+      { TILDE }
   | "~" lowercase identchar * ':'
       { let s = Lexing.lexeme lexbuf in
         let name = String.sub s 1 (String.length s - 2) in
@@ -382,6 +383,7 @@ rule token = parse
 
   | "!=" { INFIXOP0 "!=" }
   | "+"  { PLUS }
+  | "+." { PLUSDOT }
   | "-"  { MINUS }
   | "-." { MINUSDOT }
 
diff --git a/parsing/parser.mly b/parsing/parser.mly
index 17faa9191..d0d12eaad 100644
--- a/parsing/parser.mly
+++ b/parsing/parser.mly
@@ -98,6 +98,12 @@ let mkuminus name arg =
   | _ ->
       mkexp(Pexp_apply(mkoperator ("~" ^ name) 1, ["", arg]))
 
+let mkuplus name arg =
+  match name, arg.pexp_desc with
+  | "+", desc -> mkexp desc
+  | _ ->
+      mkexp(Pexp_apply(mkoperator ("~" ^ name) 1, ["", arg]))
+
 let rec mktailexp = function
     [] ->
       ghexp(Pexp_construct(Lident "[]", None, false))
@@ -281,6 +287,7 @@ let pat_of_label lbl =
 %token OR
 /* %token PARSER */
 %token PLUS
+%token PLUSDOT
 %token <string> PREFIXOP
 %token PRIVATE
 %token QUESTION
@@ -356,10 +363,10 @@ The precedences must be listed from low to high.
 %left     INFIXOP0 EQUAL LESS GREATER   /* expr (e OP e OP e) */
 %right    INFIXOP1                      /* expr (e OP e OP e) */
 %right    COLONCOLON                    /* expr (e :: e :: e) */
-%left     INFIXOP2 PLUS MINUS MINUSDOT  /* expr (e OP e OP e) */
+%left     INFIXOP2 PLUS PLUSDOT MINUS MINUSDOT  /* expr (e OP e OP e) */
 %left     INFIXOP3 STAR                 /* expr (e OP e OP e) */
 %right    INFIXOP4                      /* expr (e OP e OP e) */
-%nonassoc prec_unary_minus              /* unary - */
+%nonassoc prec_unary_minus prec_unary_plus /* unary - */
 %nonassoc prec_constant_constructor     /* cf. simple_expr (C versus C x) */
 %nonassoc prec_constr_appl              /* above AS BAR COLONCOLON COMMA */
 %nonassoc below_SHARP
@@ -877,6 +884,8 @@ expr:
       { mkinfix $1 $2 $3 }
   | expr PLUS expr
       { mkinfix $1 "+" $3 }
+  | expr PLUSDOT expr
+      { mkinfix $1 "+." $3 }
   | expr MINUS expr
       { mkinfix $1 "-" $3 }
   | expr MINUSDOT expr
@@ -901,6 +910,8 @@ expr:
       { mkinfix $1 ":=" $3 }
   | subtractive expr %prec prec_unary_minus
       { mkuminus $1 $2 }
+  | additive expr %prec prec_unary_plus
+      { mkuplus $1 $2 }
   | simple_expr DOT label_longident LESSMINUS expr
       { mkexp(Pexp_setfield($1, $3, $5)) }
   | simple_expr DOT LPAREN seq_expr RPAREN LESSMINUS expr
@@ -1481,6 +1492,7 @@ operator:
   | INFIXOP3                                    { $1 }
   | INFIXOP4                                    { $1 }
   | PLUS                                        { "+" }
+  | PLUSDOT                                     { "+." }
   | MINUS                                       { "-" }
   | MINUSDOT                                    { "-." }
   | STAR                                        { "*" }
@@ -1592,4 +1604,8 @@ subtractive:
   | MINUS                                       { "-" }
   | MINUSDOT                                    { "-." }
 ;
+additive:
+  | PLUS                                        { "+" }
+  | PLUSDOT                                     { "+." }
+;
 %%
diff --git a/stdlib/printf.ml b/stdlib/printf.ml
index 6121daf3f..2d2ea5e35 100644
--- a/stdlib/printf.ml
+++ b/stdlib/printf.ml
@@ -445,14 +445,15 @@ let format_float_lexeme =
 
   let make_valid_float_lexeme s =
     (* Check if s is already a valid lexeme:
-       in this case do nothing (we should still remove a leading +!),
+       in this case do nothing (unless we got a leading '+' character that we
+       should remove ?),
        otherwise turn s into a valid Caml lexeme. *)
     let l = String.length s in
     let rec valid_float_loop i =
       if i >= l then s ^ "." else
       match s.[i] with
       (* Sure, this is already a valid float lexeme. *)
-      | '.' | 'e' | 'E'  -> s
+      | '.' | 'e' | 'E' -> s
       | _ -> valid_float_loop (i + 1) in
 
     valid_float_loop 0 in