>an error of translation from natural language to formal language
Really? Programming languages are all formal languages, which means all human-made errors in algorithms wouldn't be "bugs" anymore. Some projects even categorize typos as bugs, so that's a unusually strict definition of "bug" in my opinion.
Sure, I guess you can understand what I said that way, but that's not what I meant. I wasn't thinking about the implementation, but the specifications.
Read again the quote I was refering to if you need better context to understand my comment.
If you have good formal specifications, you should be able to produce the corresponding code. Any error in that phase should be considered a bug, and yes, a typo should fit that category, if it makes the code deviate from the specs.
But an error in the step of translating the requirements (usually explained in natural language) to specifications (usually described formally) isn't a bug, it's a translation error.