diff --git a/lib/lua/runtime.sx b/lib/lua/runtime.sx
index b3b95eaa..99371195 100644
--- a/lib/lua/runtime.sx
+++ b/lib/lua/runtime.sx
@@ -1493,3 +1493,27 @@
     (if (>= i (len args))
         (list)
         (cons (nth args i) (lua-varargs-tail args (+ i 1))))))
+
+;; preload standard libs in package.loaded
+(dict-set! __package-loaded "string" string)
+(dict-set! __package-loaded "math" math)
+(dict-set! __package-loaded "table" table)
+(dict-set! __package-loaded "io" io)
+(dict-set! __package-loaded "os" os)
+(dict-set! __package-loaded "coroutine" coroutine)
+(dict-set! __package-loaded "package" package)
+(dict-set! __package-loaded "_G" _G)
+
+(define arg {})
+
+;; preload debug stub
+(define debug {})
+(dict-set! debug "traceback" (fn (&rest args) (if (> (len args) 0) (first args) "")))
+(dict-set! debug "getinfo" (fn (&rest args) {}))
+(dict-set! debug "sethook" (fn (&rest args) nil))
+(dict-set! debug "gethook" (fn () nil))
+(dict-set! debug "getlocal" (fn (&rest args) nil))
+(dict-set! debug "setlocal" (fn (&rest args) nil))
+(dict-set! debug "getupvalue" (fn (&rest args) nil))
+(dict-set! debug "setupvalue" (fn (&rest args) nil))
+(dict-set! __package-loaded "debug" debug)
diff --git a/lib/lua/scoreboard.json b/lib/lua/scoreboard.json
index 41028753..29dc0907 100644
--- a/lib/lua/scoreboard.json
+++ b/lib/lua/scoreboard.json
@@ -11,20 +11,12 @@
   "top_failure_modes": [
     [
       "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      5
-    ],
-    [
-      "parse error",
-      3
+      8
     ],
     [
       "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
       2
     ],
-    [
-      "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: module 'string' not found\\\\",
-      1
-    ],
     [
       "timeout",
       1
@@ -33,16 +25,20 @@
       "undefined symbol: collectgarbage\\",
       1
     ],
+    [
+      "parse error",
+      1
+    ],
     [
       "undefined symbol: setfenv\\",
       1
     ],
     [
-      "undefined symbol: T\\",
+      "arith type error",
       1
     ],
     [
-      "undefined symbol: arg\\",
+      "undefined symbol: T\\",
       1
     ]
   ],
@@ -62,20 +58,20 @@
     {
       "name": "attrib.lua",
       "status": "fail",
-      "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: module 'string' not found\\\\",
-      "ms": 5744
+      "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
+      "ms": 5747
     },
     {
       "name": "big.lua",
       "status": "timeout",
       "reason": "per-test timeout",
-      "ms": 8004
+      "ms": 8007
     },
     {
       "name": "calls.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 4612
+      "ms": 4595
     },
     {
       "name": "checktable.lua",
@@ -87,7 +83,7 @@
       "name": "closure.lua",
       "status": "fail",
       "reason": "undefined symbol: collectgarbage\\",
-      "ms": 6160
+      "ms": 6175
     },
     {
       "name": "code.lua",
@@ -99,7 +95,7 @@
       "name": "constructs.lua",
       "status": "fail",
       "reason": "parse error",
-      "ms": 2720
+      "ms": 2589
     },
     {
       "name": "db.lua",
@@ -111,13 +107,13 @@
       "name": "errors.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 3172
+      "ms": 2997
     },
     {
       "name": "events.lua",
       "status": "fail",
       "reason": "undefined symbol: setfenv\\",
-      "ms": 6976
+      "ms": 6803
     },
     {
       "name": "files.lua",
@@ -134,14 +130,14 @@
     {
       "name": "literals.lua",
       "status": "fail",
-      "reason": "parse error",
-      "ms": 1786
+      "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
+      "ms": 1783
     },
     {
       "name": "locals.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 1707
+      "ms": 1623
     },
     {
       "name": "main.lua",
@@ -152,44 +148,44 @@
     {
       "name": "math.lua",
       "status": "fail",
-      "reason": "parse error",
-      "ms": 2475
+      "reason": "arith type error",
+      "ms": 3864
     },
     {
       "name": "nextvar.lua",
       "status": "fail",
       "reason": "undefined symbol: T\\",
-      "ms": 6743
+      "ms": 6725
     },
     {
       "name": "pm.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 5928
+      "ms": 5622
     },
     {
       "name": "sort.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
-      "ms": 1169
+      "ms": 1158
     },
     {
       "name": "strings.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 3872
+      "ms": 3811
     },
     {
       "name": "vararg.lua",
       "status": "fail",
-      "reason": "undefined symbol: arg\\",
-      "ms": 2140
+      "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
+      "ms": 2111
     },
     {
       "name": "verybig.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
-      "ms": 553
+      "ms": 563
     }
   ]
 }
\ No newline at end of file
diff --git a/lib/lua/scoreboard.md b/lib/lua/scoreboard.md
index 9c23636f..c4e3a9c9 100644
--- a/lib/lua/scoreboard.md
+++ b/lib/lua/scoreboard.md
@@ -5,15 +5,14 @@ fail=15 timeout=1 skip=8 total=24
 
 ## Top failure modes
 
-- **5x** other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\
-- **3x** parse error
+- **8x** other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\
 - **2x** other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio
-- **1x** other: Unhandled exception: \"Unhandled exception: \\\"lua: module 'string' not found\\
 - **1x** timeout
 - **1x** undefined symbol: collectgarbage\
+- **1x** parse error
 - **1x** undefined symbol: setfenv\
+- **1x** arith type error
 - **1x** undefined symbol: T\
-- **1x** undefined symbol: arg\
 
 ## Per-test results
 
@@ -21,25 +20,25 @@ fail=15 timeout=1 skip=8 total=24
 |---|---|---|---:|
 | all.lua | skip | driver uses dofile to chain other tests | 0 |
 | api.lua | skip | requires testC (C debug library) | 0 |
-| attrib.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: module 'string' not found\\ | 5744 |
-| big.lua | timeout | per-test timeout | 8004 |
-| calls.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4612 |
+| attrib.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 5747 |
+| big.lua | timeout | per-test timeout | 8007 |
+| calls.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4595 |
 | checktable.lua | skip | internal debug helpers | 0 |
-| closure.lua | fail | undefined symbol: collectgarbage\ | 6160 |
+| closure.lua | fail | undefined symbol: collectgarbage\ | 6175 |
 | code.lua | skip | bytecode inspection via debug library | 0 |
-| constructs.lua | fail | parse error | 2720 |
+| constructs.lua | fail | parse error | 2589 |
 | db.lua | skip | debug library | 0 |
-| errors.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3172 |
-| events.lua | fail | undefined symbol: setfenv\ | 6976 |
+| errors.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 2997 |
+| events.lua | fail | undefined symbol: setfenv\ | 6803 |
 | files.lua | skip | io library | 0 |
 | gc.lua | skip | collectgarbage / finalisers | 0 |
-| literals.lua | fail | parse error | 1786 |
-| locals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1707 |
+| literals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1783 |
+| locals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1623 |
 | main.lua | skip | standalone interpreter driver | 0 |
-| math.lua | fail | parse error | 2475 |
-| nextvar.lua | fail | undefined symbol: T\ | 6743 |
-| pm.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 5928 |
-| sort.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 1169 |
-| strings.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3872 |
-| vararg.lua | fail | undefined symbol: arg\ | 2140 |
-| verybig.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 553 |
+| math.lua | fail | arith type error | 3864 |
+| nextvar.lua | fail | undefined symbol: T\ | 6725 |
+| pm.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 5622 |
+| sort.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 1158 |
+| strings.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3811 |
+| vararg.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 2111 |
+| verybig.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 563 |
diff --git a/lib/lua/tokenizer.sx b/lib/lua/tokenizer.sx
index 6a09788d..a31dff38 100644
--- a/lib/lua/tokenizer.sx
+++ b/lib/lua/tokenizer.sx
@@ -224,11 +224,7 @@
               (begin
                 (read-decimal-digits!)
                 (when
-                  (and
-                    (< pos src-len)
-                    (= (cur) ".")
-                    (< (+ pos 1) src-len)
-                    (lua-digit? (lua-peek 1)))
+                  (and (< pos src-len) (= (cur) "."))
                   (begin (advance! 1) (read-decimal-digits!)))
                 (read-exp-part!)
                 (parse-number (slice src start pos)))))))
diff --git a/plans/lua-on-sx.md b/plans/lua-on-sx.md
index 5778cd39..142551bb 100644
--- a/plans/lua-on-sx.md
+++ b/plans/lua-on-sx.md
@@ -82,6 +82,7 @@ Each item: implement → tests → tick box → update progress log.
 
 _Newest first. Agent appends on every commit._
 
+- 2026-04-24: lua: scoreboard iteration — trailing-dot number literals (`5.`), preload stdlibs in `package.loaded` (`string`/`math`/`table`/`io`/`os`/`coroutine`/`package`/`_G`), `arg` stub, `debug` module stub. Assertion-failure count 4→**8**, parse errors 3→**1**, call-non-fn stable, module-not-found gone.
 - 2026-04-24: lua: scoreboard iteration — **vararg `...` transpile**. Parser already emitted `(lua-vararg)`; transpile now: (a) binds `__varargs` in function body when `is-vararg`, (b) emits `__varargs` for `...` uses; `lua-varargs`/`lua-spread-last-multi` runtime helpers spread multi in last call-arg and last table-pos positions. Eliminated all 6× "transpile: unsupported" failures; top-5 now all real asserts. 353 unit tests.
 - 2026-04-24: lua: scoreboard iteration — added `rawget`/`rawset`/`rawequal`/`rawlen`, `loadstring`/`load`, `select`, `assert`, `_G`, `_VERSION`. Failure mix now 6×vararg-transpile / 4×real-assertion / 3×parse / 2×call-non-fn / 1×timeout (was 14 parse + 1 print undef at baseline); tests now reach deep into real assertions. Still 0/16 runnable — next targets: vararg transpile, goto, loadstring-compile depth. 347 unit tests.
 - 2026-04-24: lua: `require`/`package` via preload-only (no filesystem search). `package.loaded` caching, nil-returning modules cache as `true`, unknown modules error. 347 tests.