Toy building block

FIG. 1 is a perspective view of a toy building block showing the design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left elevation view thereof;

FIG. 7 is a right elevation view thereof;

FIG. 8 is a sectional view through FIG. 2 at 8 — 8 ;

FIG. 9 is a sectional view through FIG. 2 at 9 — 9 ; and,

FIG. 10 is a perspective view thereof, together with a plurality of other like blocks, shown in broken lines, and forming no part of the claimed design.