Add OP_GREATERTHAN page

Author: thunderbiscuit

.vitepress/config.js

@@ -173,7 +173,7 @@ export default {
         { text: "<code>157 | OP_NUMEQUALVERIFY</code>", link: "/opcodes/OP_NUMEQUALVERIFY.md" },
         { text: "<code>158 | OP_NUMNOTEQUAL</code>", link: "/opcodes/OP_NUMNOTEQUAL.md" },
         { text: "<code>159 | OP_LESSTHAN</code>", link: "/opcodes/OP_LESSTHAN.md" },
-        { text: "<code>160 | 🚧 OP_GREATERTHAN</code>", link: "/opcodes/OP_GREATERTHAN.md" },
+        { text: "<code>160 | OP_GREATERTHAN</code>", link: "/opcodes/OP_GREATERTHAN.md" },
         { text: "<code>161 | 🚧 OP_LESSTHANOREQUAL</code>", link: "/opcodes/OP_LESSTHANOREQUAL.md" },
         { text: "<code>162 | 🚧 OP_GREATERTHANOREQUAL</code>", link: "/opcodes/OP_GREATERTHANOREQUAL.md" },
         { text: "<code>163 | 🚧 OP_MIN</code>", link: "/opcodes/OP_MIN.md" },

opcodes/OP_GREATERTHAN.md

@@ -1,5 +1,59 @@
-# Work In Progress
+# OP_GREATERTHAN
 
-:::warning
-This page has not yet been written. If you have experience with bitcoin Script and would like to contribute, please do! You can open a PR [on the repository for this website](https://github.com/thunderbiscuit/opcode-explained).
+:::info
+**Opcode number:** 160
+**Byte representation:** `0xa0`
+**Short description:** Pop the top two items; push 1 if the second is greater than the top, 0 otherwise.
 :::
+
+`OP_GREATERTHAN` compares the top two items on the stack as integers. If the second item is greater than the top item, it pushes 1 (true) onto the stack. If not, it pushes an empty array (false). Both items are removed from the stack after the comparison.
+
+### Operation
+
+1.	Take the top item (a) and the second item (b) from the stack.
+2.	Compare the two items:
+	- If b > a, push 1 (true) onto the stack.
+	- Otherwise, push an empty array (false) onto the stack.
+3.	Remove the original items from the stack.
+
+### Notes
+
+- Both items must be valid integers. Bitcoin Script interprets byte arrays up to **4 bytes** as integers.
+- An empty array ([]) is treated as 0 when compared.
+- If there are fewer than two items on the stack when `OP_GREATERTHAN` is executed, the script will fail.
+
+## Examples
+
+### Example 1: Second item is greater than the top item
+
+```shell
+# ASM script
+OP_3 OP_2 OP_GREATERTHAN
+
+# Raw script
+5352a0
+
+# Stack (before OP_GREATERTHAN)
+2  # top
+3
+
+# Stack (after OP_GREATERTHAN)
+1  # true, as 3 > 2
+```
+
+### Example 2: Comparing two zeros
+
+```shell
+# ASM script
+OP_PUSHBYTES_1 00 OP_0 OP_GREATERTHAN
+
+# Raw script
+0100009f
+
+# Stack (before OP_GREATERTHAN)
+[] # top (zero)
+0  # second (zero)
+
+# Stack (after OP_GREATERTHAN)
+[]  # false
+```