4. A method according to claim 3 further comprising the step of: placing all 0-cells on created chains in two dot-files having the following format: EQU &lt;cell identifier&gt;&lt;group number&gt;&lt;chain number&gt;&lt;cell index&gt;, where the &lt;cell index&gt; is a sequential index of a 0-cell in the chain.
4. A method according to claim 3 further comprising the step of: placing all 0-cells on created chains in two dot-files having the following format: EQU &lt;cell identifier&gt;&lt;group number&gt;&lt;chain number&gt;&lt;cell index&gt;, where the &lt;cell index&gt; is a sequential index of a 0-cell in the chain. 5. A method according to claim 4 further comprising the step of: if a b 0-cell in a dot-file belongs to two different chains, forming a record of a grid file having the following format: EQU &lt;amended group2&gt;&lt;A/B&gt;&lt;chain1 chain2&gt; . . . &lt;index1 index2&gt;&lt;cell id&gt;.