There are provided a negative dye-containing curable composition, comprising an alkali-soluble binder, an organic solvent-soluble dye, a photopolymerization initiator and a radical-polymerizable monomer, wherein: the ratio yx of the mass of the radical-polymerizable monomer y to the mass of the alkali-soluble binder x is greater than or equal to 5. In one implementation, an implantable system senses cardiac output and arterial pressure parameters and shocks the heart in inverse relation to the arterial pressure, if the cardiac output is insufficient. The tile includes a receiver within which the outer hook portion of the hook member is received, and blocking structure that prevents engagement with the outer hook portion. The housing body a view opening. , the likelihood that a user intended a particular output, but various features of the device provide additional variants that are not based solely on frequency and rather are provided by various logic structures resident on the device.