diff --git a/desktop/sources/scripts/lib/theme.js b/desktop/sources/scripts/lib/theme.js
index 87e3ab3..8ae7708 100644
--- a/desktop/sources/scripts/lib/theme.js
+++ b/desktop/sources/scripts/lib/theme.js
@@ -28,7 +28,7 @@ function Theme (_default) {
 
   this.load = function (data) {
     const theme = parse(data)
-    if (!validate(theme)) { console.warn('Theme', 'Not a theme', theme); return }
+    if (!validate(theme)) { return }
     console.log('Theme', `Loaded theme!`)
     this.el.innerHTML = `:root { --background: ${theme.background}; --f_high: ${theme.f_high}; --f_med: ${theme.f_med}; --f_low: ${theme.f_low}; --f_inv: ${theme.f_inv}; --b_high: ${theme.b_high}; --b_med: ${theme.b_med}; --b_low: ${theme.b_low}; --b_inv: ${theme.b_inv}; }`
     localStorage.setItem('theme', JSON.stringify(theme))
diff --git a/desktop/sources/scripts/library.js b/desktop/sources/scripts/library.js
index 9a2c756..647d6a6 100644
--- a/desktop/sources/scripts/library.js
+++ b/desktop/sources/scripts/library.js
@@ -91,4 +91,21 @@ function Library (ronin) {
   this.of = function (h, k) {
     return h[k]
   }
+
+  // Math
+
+  this.add = function (a, b) {
+    return a + b
+  }
+
+  this.sub = function (a, b) {
+    return a - b
+  }
+
+  this.mul = function (a, b) {
+    return a * b
+  }
+  this.div = function (a, b) {
+    return a / b
+  }
 }
diff --git a/examples/guides.lisp b/examples/guides.lisp
index 079752f..c6bff1a 100644
--- a/examples/guides.lisp
+++ b/examples/guides.lisp
@@ -16,5 +16,21 @@
       (pos 0 (of (frame) "h"))) 
     1 "red")
 
-  (stroke (line (pos 0 0) (pos (of (frame) "w") (of (frame) "h"))) 1 "red")
+  (stroke 
+    (line 
+      (pos (div (of (frame) "w") 2) 0) 
+      (pos (div (of (frame) "w") 2) (of (frame) "h"))) 
+    1 "red")
+
+  (stroke 
+    (line 
+      (pos 0 (div (of (frame) "h") 2)) 
+      (pos (div (of (frame) "w") 2) (of (frame) "h"))) 
+    1 "#72dec2")
+
+  (stroke 
+    (line 
+      (pos (div (of (frame) "w") 2) 0) 
+      (pos (of (frame) "w") (div (of (frame) "h") 2))) 
+    1 "#72dec2")
 )
\ No newline at end of file