diff --git a/composer.json b/composer.json
index 3f2c5950..2a90156b 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,6 @@
"phpstan/phpstan": "^1.12",
"phan/phan": "^5.4",
"phpstan/extension-installer": "^1.4",
- "phpstan/phpstan-strict-rules": "^1.6",
"phpunit/phpunit": "^9",
"phpstan/phpstan-deprecation-rules": "^1.2",
"yamadashy/phpstan-friendly-formatter": "^1.1"
diff --git a/www/admin/class_test.convert.colors.php b/www/admin/class_test.convert.colors.php
index a4c980cb..6754aa51 100644
--- a/www/admin/class_test.convert.colors.php
+++ b/www/admin/class_test.convert.colors.php
@@ -54,7 +54,7 @@ function display(string $color, string $text, string $text_add): string
["{COLOR}", "{TEXT}", "{CSS}"],
[
$color,
- $text . ($text_add ? '
' . $text_add : ''),
+ $text . (!empty($text_add) ? '
' . $text_add : ''),
$css
],
$template
diff --git a/www/admin/class_test.math.php b/www/admin/class_test.math.php
index 287dc78f..d3af1f39 100644
--- a/www/admin/class_test.math.php
+++ b/www/admin/class_test.math.php
@@ -23,7 +23,6 @@ $log = new CoreLibs\Logging\Logging([
'log_file_id' => $LOG_FILE_ID,
'log_per_date' => true,
]);
-$_math = new CoreLibs\Convert\Math();
$math_class = 'CoreLibs\Convert\Math';
// define a list of from to color sets for conversion test
@@ -35,13 +34,9 @@ print "