title: awk to compare multiple columns in 2 files
body: <p>I would like to compare multiple columns from 2 files and NOT print lines matching my criteria.
  An example of this would be:</p>
  
  <p>file1</p>
  
  <pre><code>apple  green  4
  orange  red  5
  apple  yellow 6
  apple  yellow 8
  grape  green 5
  </code></pre>
  
  <p>file2</p>
  
  <pre><code>apple  yellow 7
  grape  green 10
  </code></pre>
  
  <p>output</p>
  
  <pre><code>apple  green  4
  orange  red  5
  apple  yellow 8
  </code></pre>
  
  <p>I want to remove lines where <code>$1</code> and <code>$2</code> from <code>file1</code> correspond to <code>$1</code> and <code>$2</code> from <code>file2</code> AND when <code>$3</code> from <code>file1</code> is smaller than <code>$3</code> from <code>file2</code>.
  I can now only do the first part of the job, that is remove lines where <code>$1</code> and <code>$2</code> from <code>file1</code> correspond to <code>$1</code> and <code>$2</code> from <code>file2</code> (fields are separated by tabs):</p>
  
  <pre><code>awk -F '\t' 'FNR == NR {a[$1FS$2]=$1; next} !($1FS$2 in a)' file2 file1
  </code></pre>
  
  <p>Could you help me apply the last condition?</p>
  
  <p>Many thanks in advance!</p>