function dCellStyle(envName) {
      if (envName.substr(0, 1) === "d") {
          return "display";
      } else {
          return "text";
      }
  }
// environment name starts with the letter 'd'.
environment name starts with the letter 'd'.
environment name starts with the letter ' d ' .
function dCellStyle(envName) {
      if (envName.substr(0, 1) === "d") {
          return "display";
      } else {
          return "text";
      }
  }
function dCellStyle ( envName ) { if ( envName . substr ( 0 , 1 ) === "d" ) { return "display" ; } else { return "text" ; } }
environment name starts with the letter 'd'.
environment name starts with the letter ' d ' .