check operator precedence for possible error; use parentheses to clarify precedence

That looks suspiciously like decompiled code. If others agree then I may delete your post.

Decompiled code is not allowed here.

Ask the owner of the source code to give it to you or have him fix it for you.

Decompiled code is stolen code. Either you are a thief, a fence, or the receiver of stolen (intellectual) property. Either way we will not be an accomplice after the fact to theft. See also https://www.mql5.com/en/forum/134317

If you post decompiled code again, you will likely be banned.

Don't tell us you found it on the 'net: if someone stole your bank details and uploaded them on to the internet, is it OK for everyone to use them because "someone uploaded it, I don't know why I can't use that"?

I agree! It is decompiled code and the reported error is also a "classic" for decompiled code!

I have deleted the code.

Post decompiled code again and you will be banned.

Only post code that you have written yourself.