# Q&A: How to Look Up the Meaning of an Unknown Math Symbol or Expression

*Cross-posted from here.*

Here’s a general workflow for identifying the meaning of an unknown mathematical symbol/expression:

- use an online tool (like webdemo.myscript.com/views/math) to convert a drawing of the symbol/expression into Latex commands
- ask ChatGPT (chat.openai.com, free version 3.5 is fine) what the math symbol/expression given by those Latex commands means
- based on ChatGPT's explanation, perform Google searches for more specific information/examples/fact-checking as needed

Here’s an demonstration on the expression $\displaystyle \sum_{i=1}^n \textrm E[X_i],$ which seems highly relevant to your specific use-case.

**Step 1: Drawing $\to$ Latex Commands**

**Step 2: Latex Commands $\to$ Summary**

**Step 3: Summary $\to$ More Specific Information / Examples / Fact-Checking**