-- perform beta reduction (if possible)
redBetaC env ((x,t):te) (CRet (EVar y)) (e:es)
  | x == y                      = redBetaC env te (CRet e) es
redBetaC env ((x,t):te) (CRet (EVar y)) (e:es)
  | x == y                      = redBetaC env te (CRet e) es
redBetaC env ((x,t):te) (CRet (EVar y)) (e:es)
  | x == y                      = redBetaC env te (CRet e) es