diff --git a/Playgrounds/prova.ipynb b/Playgrounds/prova.ipynb
new file mode 100644
index 0000000..a4996bb
--- /dev/null
+++ b/Playgrounds/prova.ipynb
@@ -0,0 +1,41 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "4ae47336",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import torch\n",
+    "B, T, D = 4, 7, 32\n",
+    "x = torch.randn(B, T, D)\n",
+    "attn_mask = torch.triu(torch.ones(T, T, dtype=torch.bool), diagonal=1)  # [T,T]\n",
+    "pad_mask  = torch.zeros(B, T, dtype=torch.bool)  # no pads\n",
+    "mha = torch.nn.MultiheadAttention(D, num_heads=4, batch_first=True)\n",
+    "y, _ = mha(x, x, x, attn_mask=attn_mask, key_padding_mask=pad_mask)  # should work\n"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "deep_learning",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.13.7"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}