user2306: The Bitcoin wiki has a page that summarizes OP_EQUAL and OP_EQUALVERIFY:

OP_EQUAL

Opcode (Hex): 135 (0x87)
Input: x1 x2
Output: True / false
Summary: Returns 1 if the inputs are exactly equal, 0 otherwise.

OP_EQUALVERIFY

Opcode (Hex): 136 (0x88)
Input: x1 x2
Output: True / false
Summary: Same as OP_EQUAL, but runs OP_VERIFY afterward.


OP_EQUALVERIFY is listed as having a return code, when it doesn't seem like it should. (OP_EQUAL OP_VERIFY wouldn't leave anything on the stack.)

user18196: If the execution of OP_EQUAL gives true, then it does not leave true/false on the stack. If it is false then it leaves false on top of the stack and stops executing. 
Bstack.push_back(fEqual ? vchTrue : vchFalse);
if (opcode == OP_EQUALVERIFY)
{
if (fEqual)
    popstack(stack);
else
    return set_error(serror, SCRIPT_ERR_EQUALVERIFY);
}

Source

2306: <p>The Bitcoin wiki has a page that summarizes <a href="https://en.bitcoin.it/wiki/Script#Bitwise_logic" rel="nofollow noreferrer">OP_EQUAL and OP_EQUALVERIFY</a>:</p>
<blockquote>
<p>OP_EQUAL</p>
<ul>
<li>Opcode (Hex): 135 (0x87)</li>
<li>Input: x1 x2</li>
<li>Output: True / false</li>
<li>Summary: Returns 1 if the inputs are exactly equal, 0 otherwise.</li>
</ul>
<p>OP_EQUALVERIFY</p>
<ul>
<li>Opcode (Hex): 136 (0x88)</li>
<li>Input: x1 x2</li>
<li>Output: True / false</li>
<li>Summary: Same as OP_EQUAL, but runs OP_VERIFY afterward.</li>
</ul>
</blockquote>
<p><code>OP_EQUALVERIFY</code> is listed as having a return code, when it doesn't seem like it should. (<code>OP_EQUAL OP_VERIFY</code> wouldn't leave anything on the stack.)</p>
 18196: <p>If the execution of OP_EQUAL gives true, then it does not leave true/false on the stack. If it is false then it leaves false on top of the stack and stops executing. </p>

<pre><code>Bstack.push_back(fEqual ? vchTrue : vchFalse);
if (opcode == OP_EQUALVERIFY)
{
if (fEqual)
    popstack(stack);
else
    return set_error(serror, SCRIPT_ERR_EQUALVERIFY);
}
</code></pre>

<p><a href="https://github.com/bitcoin/bitcoin/blob/0.10/src/script/interpreter.cpp#L634-641" rel="nofollow">Source</a></p>
