ketli -ketl- experimental gismu

x1 is a kettle for/containing x2

In definition:

braketi
x1 is a bra or ket (mathematical object/notation) meaning/denoting/representing (object/information) x2 with properties x3

In notes:

vektori
x1 is a vector (mathematical object/number/operator) representing or meaning (object/information) x2 with properties x3