quaternary mathematical operator: (left) convolution (a★b)(c) in structure d
a, b are integrable functions; c is the variable of input of the convolution a★b; d is the structure in which these objects and the convolution live; the convolution is applied from the left (subject to context and definitions). Domains of integration and characteristics of the integrand, etc., can be defined by d and/or by context. See also: di'ei'o'au.