In reading, spelling, or math, confusion of updown directionality of letters or numbers, e.g., m for w, 6 for 9, etc.

The confusion of up/down directionality of letters or numbers in reading, spelling, or math. For example, "m" for "w," "6" for "9," etc.

the physical number of inversions on a roller coaster. This will be half the number traveled on a shuttle roller coaster with inversions. To counted as an inversion the element must turn rides a full 180° upside-down.

A condition in which temperature increases with height through a layer of the atmosphere. Vertical motion is restricted in this very stable air mass. Inversions are common during late night and early morning hours - especially in mountainous terrain - during the summer on clear nights. This type of inversion usually dissipates with daytime heating. Inversions aloft caused by large scale subsidence may persist for several days.

reversal or "flipping" of letters either horizontally or vertically, i.e.: p - d, or d - b, m - w, u - n. Not unusual for Emergent writers or readers.