[…] being there as an assistant, he actually seemed […] to be the aider and abettor of a system which filled him with honest disgust and indignation, https://archive.org/details/venturesoflifead00dickrich/page/73/mode/1up?q=aider

Notwithstanding his clothes, there was an air of breeding about him, unconcealable, a thing apart, even, from his good looks.

Moreover, the function f(y,t) is Lipschitzian […]

Coordinate term: Tejano