diff --git a/beautiful-racket-demo/basic-demo-nth/tokenizer.rkt b/beautiful-racket-demo/basic-demo-nth/tokenizer.rkt
index 02d6b73..d07620c 100644
--- a/beautiful-racket-demo/basic-demo-nth/tokenizer.rkt
+++ b/beautiful-racket-demo/basic-demo-nth/tokenizer.rkt
@@ -1,7 +1,5 @@
 #lang br
-(require parser-tools/lex
-         (prefix-in : parser-tools/lex-sre)
-         brag/support)
+(require brag/support)
 (provide tokenize basic-lexer)
 
 (define-lex-abbrevs
diff --git a/beautiful-racket-demo/basic-demo/tokenizer.rkt b/beautiful-racket-demo/basic-demo/tokenizer.rkt
index 9a931f5..06ad50a 100644
--- a/beautiful-racket-demo/basic-demo/tokenizer.rkt
+++ b/beautiful-racket-demo/basic-demo/tokenizer.rkt
@@ -1,7 +1,5 @@
 #lang br
-(require parser-tools/lex
-         (prefix-in : parser-tools/lex-sre)
-         brag/support)
+(require brag/support)
 (provide (all-defined-out))
 
 (define basic-lexer
diff --git a/beautiful-racket-demo/bf-demo/reader.rkt b/beautiful-racket-demo/bf-demo/reader.rkt
index a54391c..16a21ff 100644
--- a/beautiful-racket-demo/bf-demo/reader.rkt
+++ b/beautiful-racket-demo/bf-demo/reader.rkt
@@ -8,7 +8,7 @@
   (datum->syntax #f module-datum))
 (provide read-syntax)
 
-(require parser-tools/lex)
+(require brag/support)
 (define (tokenize port)
   (define (next-token)
     (define our-lexer
diff --git a/beautiful-racket-demo/bf-demo/test-tokenizer.rkt b/beautiful-racket-demo/bf-demo/test-tokenizer.rkt
index e7c3adf..ad0a2f4 100644
--- a/beautiful-racket-demo/bf-demo/test-tokenizer.rkt
+++ b/beautiful-racket-demo/bf-demo/test-tokenizer.rkt
@@ -1,5 +1,5 @@
 #lang br
-(require parser-tools/lex brag/support)
+(require brag/support)
 
 (define+provide (tokenize ip)
   (define get-token
diff --git a/beautiful-racket-demo/hdl-demo/tokenizer.rkt b/beautiful-racket-demo/hdl-demo/tokenizer.rkt
index 25a350d..2bc272c 100644
--- a/beautiful-racket-demo/hdl-demo/tokenizer.rkt
+++ b/beautiful-racket-demo/hdl-demo/tokenizer.rkt
@@ -1,6 +1,5 @@
 #lang br
-(require parser-tools/lex parser-tools/lex-sre
-         brag/support
+(require brag/support
          racket/string)
 
 (provide tokenize)
@@ -10,10 +9,10 @@
       (lexer-src-pos
        [(eof) eof]
        [(union
-         (seq "/*" (complement (seq any-string "*/" any-string)) "*/")
-         (seq "//" (repetition 1 +inf.0 (char-complement #\newline)) #\newline))
+         (:seq "/*" (complement (:seq any-string "*/" any-string)) "*/")
+         (:seq "//" (repetition 1 +inf.0 (char-complement #\newline)) #\newline))
         (token 'COMMENT lexeme #:skip? #t)]
-       [(union #\tab #\space #\newline) (get-token input-port)]
+       [(union #\tab #\space #\newline) (return-without-pos (get-token input-port))]
        [(union "CHIP" "IN" "OUT" "PARTS:") lexeme]
        [(char-set "[]{}(),;=.") lexeme]
        ["true" (token 'TRUE #t)]
@@ -21,6 +20,6 @@
        [(repetition 1 +inf.0 numeric) (token 'NUMBER (string->number lexeme))]
        ; bugaboo: "10" is ambiguous: number or binary number?
        [(repetition 1 +inf.0 (char-set "01")) (token 'BINARY-NUMBER (string->number lexeme 2))]
-       [(seq (repetition 1 1 alphabetic) (repetition 0 +inf.0 (union alphabetic numeric "-"))) (token 'ID (string->symbol lexeme))]))
+       [(:seq (repetition 1 1 alphabetic) (repetition 0 +inf.0 (union alphabetic numeric "-"))) (token 'ID (string->symbol lexeme))]))
     (get-token input-port))  
   next-token)
diff --git a/beautiful-racket-demo/hdl-tst-demo/tokenizer.rkt b/beautiful-racket-demo/hdl-tst-demo/tokenizer.rkt
index a5255ce..21442d4 100644
--- a/beautiful-racket-demo/hdl-tst-demo/tokenizer.rkt
+++ b/beautiful-racket-demo/hdl-tst-demo/tokenizer.rkt
@@ -1,6 +1,5 @@
 #lang br
-(require parser-tools/lex parser-tools/lex-sre
-         brag/support
+(require brag/support
          racket/string)
 
 (provide tokenize)
@@ -10,12 +9,12 @@
       (lexer-src-pos
        [(eof) eof]
         [(union
-         (seq "/*" (complement (seq any-string "*/" any-string)) "*/")
-         (seq "//" (repetition 1 +inf.0 (char-complement #\newline)) #\newline))
+         (:seq "/*" (complement (:seq any-string "*/" any-string)) "*/")
+         (:seq "//" (repetition 1 +inf.0 (char-complement #\newline)) #\newline))
         (token 'COMMENT lexeme #:skip? #t)]
-       [(union #\tab #\space #\newline) (get-token input-port)]
+       [(union #\tab #\space #\newline) (return-without-pos (get-token input-port))]
        [(union "load" "output-list" "output-file" "compare-to" "set" "eval" "output" (char-set ",;")) lexeme]
-       [(seq "%" (repetition 1 +inf.0 (union alphabetic numeric (char-set ".")))) (token 'FORMAT-STRING lexeme)]
+       [(:seq "%" (repetition 1 +inf.0 (union alphabetic numeric (char-set ".")))) (token 'FORMAT-STRING lexeme)]
        [(repetition 1 +inf.0 numeric) (token 'VAL (string->number lexeme))]
        [(repetition 1 +inf.0 (union alphabetic numeric (char-set "-."))) (token 'ID lexeme)]))
     (get-token input-port))  
diff --git a/beautiful-racket-demo/txtadv-demo/tokenizer.rkt b/beautiful-racket-demo/txtadv-demo/tokenizer.rkt
index d004f25..2001188 100644
--- a/beautiful-racket-demo/txtadv-demo/tokenizer.rkt
+++ b/beautiful-racket-demo/txtadv-demo/tokenizer.rkt
@@ -1,6 +1,5 @@
 #lang br
-(require parser-tools/lex parser-tools/lex-sre
-         brag/support
+(require brag/support
          racket/string)
 
 (provide tokenize)
@@ -10,13 +9,13 @@
       (lexer
        [(eof) eof]
        [(union
-         (seq "/*" (complement (seq any-string "*/" any-string)) "*/")
-         (seq "//" (repetition 1 +inf.0 (char-complement #\newline)) #\newline))
+         (:seq "/*" (complement (:seq any-string "*/" any-string)) "*/")
+         (:seq "//" (repetition 1 +inf.0 (char-complement #\newline)) #\newline))
         (token 'COMMENT lexeme #:skip? #t)]
        [(union #\tab #\space #\newline) (get-token input-port)]
        [(repetition 1 +inf.0 (union upper-case (char-set "="))) lexeme]
-       [(seq "\"" (complement (seq any-string "\"" any-string)) "\"") (token 'STRING (string-trim lexeme "\""))]
-       [(seq "---"
+       [(:seq "\"" (complement (:seq any-string "\"" any-string)) "\"") (token 'STRING (string-trim lexeme "\""))]
+       [(:seq "---"
              (repetition 1 +inf.0 (union alphabetic numeric punctuation))
              "---") (token 'DASHED-NAME (string->symbol (string-trim lexeme "-" #:repeat? #t)))]
        [(repetition 1 +inf.0 (union alphabetic numeric (char-set "-!?.#'")))