ALT A physicist, holds a piece of paper with "dy/dx" written on it. A gagged mathematician looks on in abject horror.

ALT Doing the unthinkable, the physicist tears apart the piece of paper into two separate halves saying "dy" and "dx", cackling with glee.

ALT What was said: I have a standard practice of writing with the thesaurus site open to make sure I paraphrase reasonably well, never using more than ~3 consecutive words directly from what I’m paraphrasing. I don’t understand how this is difficult for people… — @generic_void How a number of people interpreted it: Let $A=\{a_i\}_{i=1}^n$ be the original text and $B=\{b_i\}_{i=1}^n$ be the paraphrased text. Then $a_i=b_i$ if and only if $i\equiv 0\pmod 4$. How I interpreted it: Let $A=\{a_i\}_{i=1}^n$ be the original text and $B=\{b_j\}_{j=1}^m$ be the paraphrased text. Then there does not exist $k\in\{1,\cdots,n-3\}$ and $r\in\{1,\cdots,m-3\}$ such that $$(a_k,a_{k+1},a_{k+2},a_{k+3})=(b_r,b_{r+1},b_{r+2},b_{r+3}).$$