# Guide for New Users¶

Approach0 is a math-aware search engine dedicated to provide better search experience for mathematical Q&A websites. This page aims to provide new users a quick tour about how to use Approach0 search engine.

## What the search engine actually looks for?¶

The current online version is serveing for demonstration purpose, with only one math Q&A site being indexed (Mathematics StackExchange). The indices cover over one million posts on Mathematics StackExchange.

## How a search query is entered?¶

### 1. Non-math keyword¶

If you only want to search non-math terms (i.e. normal text), just type the keyword(s) like what you normally do on a typical search engine:

(After you have done a keyword, hit Enter to finish editing, then hit Enter again or click search button to actually perform search)

### 2. Math keyword¶

To input math keyword is also very intuitive, user does not have to know TeX to input a math expression on search box. Below is an example of inputting math expression $$\log(x)$$:

You can either type \log(x) or log(x) directly on search box to input $$\log(x)$$. Although this works, the recommended way is first type a dollar sign  (to indicate the next keyword you are entering is a math keyword) followed by your math expression.

This is important when you are entering a math expression that is hard to tell whether it is truly a math or a regular term. (e.g. AI can be interpreted as a matrix multiplication in math or “Artificial Intelligence” in English)

### 3. Mixed keywords¶

You can mix non-math and math keywords together (in any order) within one query:

One restriction: You are limited to enter less than 5 math keywords and less than 21 non-math keywords in one query.

## Other tips¶

• There are some math symbols that you may find not intuitive or not familiar on how to type directly into query input box (such as $$\infty$$, $$\Theta$$ and $$\perp$$). In these cases, click “handy pad” under search box for a number of buttons to help you enter math symbols.
• The URL displayed on your browser uniquely determines a query and page you are searching for. So you can show this URL to others to refer a query.
• We support copy-paste in query input box. For math keyword, paste a/b and $$a/b$$ into query box both result in the same math expression $$\dfrac a b$$.
• You can edit or delete a math keyword by clicking the ✐  or ×  icon on the right of the keyword. You can also delete (but no edit option) a non-math keyword by clicking the ×  icon on the right of the keyword.
• If you do not get any search result (“No hit found”), try to reduce the complexity of your math expression a little bit. Also, check if your raw query is somewhat malformed, by clicking the raw query link under search box. Some typical malformed TeX snippets:
• a^(1+2+3) (should be a^{1+2+3})
• sin(x) (should be \sin(x))
• How to manually enter (without the assistance of “handy pad”) integrals with both lower and upper bounds?
• This is a little tricky, the wrong way:
• The right way: Use arrow key to move cursor to the rightmost and hit a ^ so it goes to upper bound edit. Then hit tab key to move cursor to edit function $$f(x)$$:

• If you know math-related TeX commands, it is often faster to edit the equivalent raw query (separate keywords by commas). For example, the above mixed keywords “concave” and “$$f’’ < 0$$” is equivalent to inputting a concave, $f''\lt 0$ in raw query box.
• You can use question mark ? on our query input box to represent a wildcard which represents any math expression except a single symbol. For example, if you want to search expression $dX_t = \ln (1+X_t^2)+ X_t dB_t$ you can type less by just searching: $? = \ln (1+X_t^2)+ ?$ In raw query, you can use \qvar{} to name wildcards which represent different expressions. For instance: $$\qvar{x} = \ln (1 + X_t^2) + \qvar{y}$$.
• Our WEB API enables developers to build their own applications based on our search engine. Search results are returned in JSON format.

## Help Approach0 improve¶

### 1. Make contribution to this project¶

Approach0 is an open-source project hosted on Github. And it is open to any brilliant idea.

Notice each time you visit approach0 there will be a “random” math question which is called “quiz conversation”, You can contribute your own quiz conversation on this page.

Click the upper-right Edit on GitHub link to improve this guide.
You can contact the author by sending a tweet with hashtag #approach0, or leave a message in this chat room on Mathematics StackExchange meta site.