From co- + type.
cotype (plural cotypes)
- (taxonomy, dated) A syntype or paratype.
- (functional analysis) A Banach space
, such that, given a sequence of independent random variables from a Rademacher distribution, 
, and a rank 
in the range from 2 to infinity, there exists a finite constant 
such that for all finite sequences 
, ![{\displaystyle \mathbb {E} _{\varepsilon }\left[\left\|\sum \limits _{i=1}^{n}\varepsilon _{i}x_{i}\right\|^{q}\right]\geq {\frac {1}{C^{q}}}\left(\sum \limits _{i=1}^{n}\|x_{i}\|^{q}\right),\quad {\text{if}}\;2\leq q<\infty }](https://wikimedia.org/api/rest_v1/media/math/render/svg/81895b4a68dbd6b50c867ca90a84f7808c1a8876)
or ![{\displaystyle \mathbb {E} _{\varepsilon }\left[\left\|\sum \limits _{i=1}^{n}\varepsilon _{i}x_{i}\right\|\right]\geq {\frac {1}{C}}\sup \|x_{i}\|,\quad {\text{if}}\;q=\infty }](https://wikimedia.org/api/rest_v1/media/math/render/svg/1b27844accb629439a0704bdf4608f37e76696cf)
.
- Coordinate term: type
