A partially impregnated preform employs a fiber layer partially impregnated with a resin to form a fiber reinforced resin composite. Input and output attributes of the candidate pair tasks are compared and consolidation confirmed if the compared input and output attributes are similar. The passageway has a yarn inlet end, a yarn outlet end and adjacent to the yarn outlet end yarn guides to constrain the tail of the yarn against lateral deflection in a longitudinal direction of the yarn carrier. The pitch difference of one section is at least double that of the adjacent sections and in the screwed-together position, in the section with the large pitch difference, the thread play and the thread tolerances are compensated and the load flank of one corner tooth of this section, with the guide flank of the other corner tooth, produces the basic bracing. The third support may contact a position along the upper rim of the musical instrument, e. A distance to the breakage point may be determined from a difference between modulation patterns of transmitted and received test signals.