Interlocking panel structure

Claim 1

A UNIT FOR USE IN A MULTI-UNIT TRANSVERSELY-RIGID WALLLIKE SFTRUCTURE FORMED OF A PLURALITY OF UNITS ARRANGED EDGE TO EDGE IN COPLANAR RELATION, SAID UNIT COMPRISING A WIDE PLATE-LIKE BODY WITH A RELATIVELY NARROW RIGID WEB DISPOSED NORMAL TO THE BODY ALONG EACH OF TWO OPPOSITE MARGINS, ONE WEB HAVING A RIGID FLANGE SPACED FROM AND SUBSTANTIALLY PARALLEL TO THE PLANE TO THE BODY AND EXTENDING OUTBOARD OF THE ADJACENT MARGIN OF THE BODY AND INCLUDING A FLAT INNER SURFACE OF SUBSTANTIAL WIDTH FACING TOWARD THE BODY, THERE BEING AN INWARDLY OFFSET LIP AT THE OUTER MARGIN OF SAID FLANGE FORMING A SHOULDER FACING TO WARD SAID ONE WEB, THE OTHER WEB HAVING A RIGID FLANGE EXTENDING TRANSVERSE OF SAID OTHER WEB AND SPACED FROM THE BODY AND EXTENDING INBOARD OF THE ADJACENT MARGIN OF THE BODY AND INCLUDING A FLAT OUTER SURFACE FACING AWAY FROM SAID PLANE, THERE BEING AN INWARDLY OFFSET LIP AT THE OUTER MARGIN OF SAID OUTER SURFACE PROJECTING BEYOND SAID FIRST-MENTIONED LIP AND FORMING A SHOULDER FACING AWAY FROM SAID OTHER WEB, THE WIDTH OF SAID SURFACES ON BOTH FLANGES BEING THE SAME SO THAT THE SHOULDER ON THE OUTBOARD EXTENDING FLANGE OF ONE UNIT MAY SNAP OVER AND TIGHTLY ENGAGE THE SHOULDER OF THE INBOARD EXTENDING FLANGE OF A LIKE JUXTAPOSED UNIT, SAID LIP FORMING A CREVICE FOR THE INSERTION OF THE END OF AN ELONGATED PRYING TOOL AND ALSO A FULCRUM FOR THE TOOL.