diff --git a/rsconcept/backend/requirements-dev-lock.txt b/rsconcept/backend/requirements-dev-lock.txt
index 15ac8ccf..632d236e 100644
--- a/rsconcept/backend/requirements-dev-lock.txt
+++ b/rsconcept/backend/requirements-dev-lock.txt
@@ -8,7 +8,7 @@ drf-spectacular-sidecar==2024.7.1
 coreapi==2.3.3
 django-rest-passwordreset==1.4.1
 cctext==0.1.4
-pyconcept==0.1.8
+pyconcept==0.1.10
 
 psycopg2-binary==2.9.9
 gunicorn==23.0.0
diff --git a/rsconcept/backend/requirements.txt b/rsconcept/backend/requirements.txt
index 8296f987..ab8455c0 100644
--- a/rsconcept/backend/requirements.txt
+++ b/rsconcept/backend/requirements.txt
@@ -8,7 +8,7 @@ drf-spectacular-sidecar==2024.7.1
 coreapi==2.3.3
 django-rest-passwordreset==1.4.1
 cctext==0.1.4
-pyconcept==0.1.8
+pyconcept==0.1.10
 
 psycopg2-binary==2.9.9
 gunicorn==23.0.0
\ No newline at end of file
diff --git a/rsconcept/frontend/index.html b/rsconcept/frontend/index.html
index dc965934..23178ceb 100644
--- a/rsconcept/frontend/index.html
+++ b/rsconcept/frontend/index.html
@@ -15,7 +15,7 @@
     <link rel="preconnect" href="https://fonts.googleapis.com" />
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
     <link
-      href="https://fonts.googleapis.com/css2?family=Rubik:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,300;1,400;1,500;1,600;1,700;1,800;1,900&family=Fira+Code:wght@300..700&family=Noto+Sans+Math&family=Noto+Sans+Symbols+2&family=Alegreya+Sans+SC:wght@100;300;400;500;700;800;900"
+      href="https://fonts.googleapis.com/css2?family=Rubik:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,300;1,400;1,500;1,600;1,700;1,800;1,900&family=Fira+Code:wght@300..700&family=Noto+Sans+Math&family=Noto+Sans+Symbols+2&family=Alegreya+Sans+SC:wght@100;300;400;500;700;800;900&family=Noto+Color+Emoji"
       rel="stylesheet"
     />
 
diff --git a/rsconcept/frontend/src/models/rslang.ts b/rsconcept/frontend/src/models/rslang.ts
index b888f8c1..f9498850 100644
--- a/rsconcept/frontend/src/models/rslang.ts
+++ b/rsconcept/frontend/src/models/rslang.ts
@@ -232,6 +232,7 @@ export enum RSErrorType {
   invalidBinding = 34836,
   localOutOfScope = 34837,
   invalidElementPredicate = 34838,
+  invalidEmptySetUsage = 34839,
   invalidArgsArity = 34840,
   invalidArgumentType = 34841,
   globalStructure = 34844,
diff --git a/rsconcept/frontend/src/styling/constants.css b/rsconcept/frontend/src/styling/constants.css
index 59807a6d..ab790391 100644
--- a/rsconcept/frontend/src/styling/constants.css
+++ b/rsconcept/frontend/src/styling/constants.css
@@ -4,9 +4,9 @@
 
 /* prettier-ignore */
 :root {
-  --font-ui:  'Alegreya Sans SC', 'Rubik', 'Segoe UI Symbol', sans-serif;
-  --font-main: 'Rubik', 'Fira Code', 'Noto Sans Math', 'Noto Sans Symbols 2', 'Segoe UI Symbol', sans-serif;
-  --font-math: 'Fira Code', 'Noto Sans Math', 'Noto Sans Symbols 2', 'Rubik', 'Segoe UI Symbol', sans-serif;
+  --font-ui:  'Alegreya Sans SC', 'Rubik', 'Noto Color Emoji', 'Segoe UI Symbol', sans-serif;
+  --font-main: 'Rubik', 'Noto Color Emoji', 'Fira Code', 'Noto Sans Math', 'Noto Sans Symbols 2', 'Segoe UI Symbol', sans-serif;
+  --font-math: 'Fira Code', 'Noto Sans Math', 'Noto Sans Symbols 2', 'Rubik', 'Noto Color Emoji', 'Segoe UI Symbol', sans-serif;
 
   /* Light Theme */
   --cl-bg-120:      hsl(000, 000%, 100%);
diff --git a/rsconcept/frontend/src/utils/labels.ts b/rsconcept/frontend/src/utils/labels.ts
index e3c0ae38..6ed02ec5 100644
--- a/rsconcept/frontend/src/utils/labels.ts
+++ b/rsconcept/frontend/src/utils/labels.ts
@@ -760,6 +760,8 @@ export function describeRSError(error: IRSErrorDescription): string {
       return `Использование имени переменной вне области действия: ${error.params[0]}`;
     case RSErrorType.invalidElementPredicate:
       return `Несоответствие типизаций операндов для оператора: ${error.params[0]}${error.params[1]}${error.params[2]}`;
+    case RSErrorType.invalidEmptySetUsage:
+      return 'Бессмысленное использование пустого множества';
     case RSErrorType.invalidArgsArity:
       return `Неверное число аргументов терм-функции: ${error.params[0]} != ${error.params[1]}`;
     case RSErrorType.invalidArgumentType: