page 83. Reduction scheme (7). The "V", on the right hand side of the arrow, should read "V{w'/w}".

page 86. Figure 5. The first clause defining F. The "M", on the right hand side of the equals, should read "\overline{M}". Here, \overline{M} denotes the result of substituting all worlds in M with some distinghuished world \bullet.