title: Gfortran compile Error: Logicals at (1) must be compared with .eqv. instead of ==
body: <p>I am compiling a fortran code using Gfortran. I never had these compile errors using Intel fortran compilers. The Gfortran compiler is complaining about the use of "==" for if statement comparisons. Specifically, it gives the error</p>
  
  <pre><code>Error: Logicals at (1) must be compared with .eqv. instead of ==
  </code></pre>
  
  <p>Can someone explain why Gfortran requires .eqv. usage instead of ==? </p>