+ <STRONG>FIELD</STRONG> <STRONG>*new_field(int</STRONG> <EM>height</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>width</EM><STRONG>,</STRONG>
+ <STRONG>int</STRONG> <EM>toprow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>leftcol</EM><STRONG>,</STRONG>
+ <STRONG>int</STRONG> <EM>offscreen</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>nbuffers</EM><STRONG>);</STRONG>
+ <STRONG>FIELD</STRONG> <STRONG>*dup_field(FIELD</STRONG> <STRONG>*</STRONG><EM>field</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>toprow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>leftcol</EM><STRONG>);</STRONG>
+ <STRONG>FIELD</STRONG> <STRONG>*link_field(FIELD</STRONG> <STRONG>*</STRONG><EM>field</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>toprow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>leftcol</EM><STRONG>);</STRONG>
+ <STRONG>int</STRONG> <STRONG>free_field(FIELD</STRONG> <STRONG>*</STRONG><EM>field</EM><STRONG>);</STRONG>