conductor.js
function set (symbol, value) {
      const element = view.find(element => element.let !== undefined && element.let[symbol] !== undefined)
      if (element !== undefined) element.let[symbol] = JSON.parse(JSON.stringify(value))
    }
function set (symbol, value) {
      const element = view.find(element => element.let !== undefined && element.let[symbol] !== undefined)
      if (element !== undefined) element.let[symbol] = JSON.parse(JSON.stringify(value))
    }
function set ( symbol , value ) { const element = view . find ( element => element . let !== undefined && element . let [ symbol ] !== undefined ) if ( element !== undefined ) element . let [ symbol ] = JSON . parse ( JSON . stringify ( value ) ) }
update value of topmost matching symbol on stack if any
update value of topmost matching symbol on stack if any