Unix is a standard set of tools commonly used in software development.

• macOS and Linux are on top of Unix
• Windows comes Unix now lol

You can navigate Unix inside a command line.

its a File Payload Data with smartness.

Notably, the entire file system only supports \(2^{16} = 32MB\) worth of space due to short address types.

For each file on the disk, we store payload data in a bunch of places scattered across the disk, and a single inode which stores the location of each block for the file in an array.

\begin{equation} \text{UNSAT} = \qty {\phi : \text{all assignment make $\phi$ false}} \end{equation}

Equivalently, we have:

\begin{equation} \text{UNSAT} = \neg \text{SAT} \end{equation}

NP = coNP IFF UNSAT is in NP

\begin{equation} \text{NP} = \text{coNP} \Leftrightarrow \text{UNSAT} \in \text{NP} \end{equation}

\(\Rightarrow\)

Because \(\text{UNSAT} \in \text{coNP}\), and we hypothesize NP = coNP, so \(\text{UNSAT} \in \text{NP}\)

\(\Leftarrow\)

Suppose UNSAT in NP, we desire that \(\text{coNP} = NP\). Let \(L \in \text{coNP}\),so \(\neg L \in \text{NP}\), since SAT is NP-complete, we can write that \(L \leq_{p} \text{SAT}\). Equivalently, we have \(L \leq_{p} \neg \text{SAT} = \text{UNSAT}\). Since \(\text{UNSAT} \in \text{coNP}\), we have \(L \in \text{NP}\).

• Investment: Paid for 50% of war bonds
• Production: ships, tanks, airplanes, etc. — encourages production
• Conservation: 5% of the world’s population production, 50% of the world’s manufactured goods — rationing, grow goods, etc.

USAYPT or USIYPT is a physics research competition ran by Greg Jacobs.

2022

My own work doc for the 2022 Tuning Forks problem is here.

General Tips

• When in doubt, ask about error prop
• ANSWER THE RESEARCH QUESTION (elevator)
• Convey that you understand basics via presentation
• Have intuition regarding phenomenon
• Be able to explain every formula from first principles
• Order of magnitude and dimension analysis
• Have clear variance in parameters (what did you vary and why)
• What does the intercepts mean on graphs?
• “Don’t be obtuse”
• Connect to simple physics terms
• Explanations needs to be simple
• Engage discussion