p20 - linear map M : K → L corresponds to box with input wire H and output wire K?

[OzYossarian]

Top paragraph of p20 says "The only thing missing at this point (at least until we meet tensor products in section 2.1.4) is linear maps M : K → L between two arbitrary Hilbert spaces. These are pictured as a box with an input wire labelled H and output labelled K". Wouldn't this box correspond to a linear map M : H → K?

Preprint Version 1.1.0

[jvdwetering]

Yeah this is a bit confusing. Fixed for next version.