;;;  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA
;;;  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA
;;;  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA  DELTA

(IN-PACKAGE #:cat)

(PROVIDE "delta")

(DEFMETHOD PRINT-KEYCONS ((car (eql :delt)) cdr stream)
  (format stream "~A" (hyphenize-list (dlop-int-ext cdr)))
  (cons car cdr))


(DEFUN SOFT-DELTA-CMPR (gmsm1 gmsm2)
  (f-cmpr (cdr gmsm1) (cdr gmsm2)))


(DEFUN DELTA-FACE (indx dmns gmsm)
  (declare
   (fixnum indx gmsm)
   (ignore dmns))
  (the absm
       (do ((pmark 1 (ash pmark 1))
	    (bmark indx)
	    (gmsm2 gmsm (ash gmsm2 -1)))
	   (nil)
         (declare (fixnum pmark bmark gmsm2))
         (when (oddp gmsm2)
	   (when (minusp (decf bmark))
	     (return-from delta-face (absm 0 (logxor gmsm pmark))))))))


(DEFUN SOFT-DELTA-FACE (indx dmns gmsm)
  (declare
   (fixnum indx dmns)
   (type soft-dlop gmsm))
  (absm 0 (d (gmsm (delta-face indx dmns (cdr gmsm))))))


(DEFUN DELTA-BNDR (dmns gmsm)
  (declare (fixnum dmns gmsm))
  (the cmbn
       (if (zerop dmns)
	   +zero-negative-cmbn+
	   (make-cmbn
            :degr (1- dmns)
            :list (do ((rslt +empty-list+)
		       (gmsm2 gmsm (ash gmsm2 -1))
		       (pmark 1 (ash pmark +1))
		       (sign 1))
		      ((zerop gmsm2) rslt)
                    (declare
		     (list rslt)
		     (fixnum gmsm2 pmark sign))
                    (when (oddp gmsm2)
		      (push (term sign (logxor gmsm pmark)) rslt)
		      (setf sign (- sign))))))))


(DEFUN SOFT-DELTA-BNDR (dmns gmsm)
  (declare
   (fixnum dmns)
   (type soft-dlop gmsm))
  (make-cmbn
   :degr (1- dmns)
   :list (mapcar #'(lambda (term)
		     (with-term (cffc gmsm) term
				(term cffc (d gmsm))))
		 (cmbn-list (delta-bndr dmns (cdr gmsm))))))


(DEFUN DELTA-DGNL (dmns gmsm)
  (declare (fixnum dmns gmsm))
  (the cmbn
       (make-cmbn
	:degr dmns
	:list (do ((rslt +empty-list+)
		   (ldegr dmns)
		   (indx (1- (integer-length gmsm)) (1- indx)))
		  ((minusp indx))
		(declare
		 (list rslt)
		 (fixnum indx))
		(when (logbitp indx gmsm)
		  (push (term 1 (tnpr
				 ldegr (logand gmsm (mask (1+ indx)))
				 (- dmns ldegr) (logandc2 gmsm (mask indx))))
                        rslt)
		  (when (minusp (decf ldegr))
		    (return rslt)))))))


(DEFUN SOFT-DELTA-DGNL (dmns gmsm)
  (declare
   (fixnum dmns)
   (type soft-dlop gmsm))
  (make-cmbn :degr dmns
	     :list (mapcar
		    #'(lambda (term)
			(with-term (cffc tnpr) term
				   (with-tnpr (degr1 gmsm1 degr2 gmsm2) tnpr
					      (term cffc
						    (tnpr degr1 (d gmsm1)
							  degr2 (d gmsm2))))))
		    (cmbn-list (delta-dgnl dmns (cdr gmsm))))))


(DEFUN DELTA-INFINITY ()
  (the simplicial-set
       (build-smst
	:cmpr #'f-cmpr
	:basis :locally-effective
	:bspn 1
	:face #'delta-face
	:intr-dgnl #'delta-dgnl
	:dgnl-strt :gnrt
	:intr-bndr #'delta-bndr
	:bndr-strt :gnrt
	:orgn '(delta-infinity))))


(DEFUN SOFT-DELTA-INFINITY ()
  (the simplicial-set
       (build-smst
	:cmpr #'soft-delta-cmpr
	:basis :locally-effective
	:bspn (d 1)
	:face #'soft-delta-face
	:intr-dgnl #'soft-delta-dgnl :dgnl-strt :gnrt
	:intr-bndr #'soft-delta-bndr :bndr-strt :gnrt
	:orgn '(soft-delta-infinity))))


(DEFUN DELTA-N-BASIS (n)
  (declare (fixnum n))
  (flet ((rslt (dmns)
	   (declare (fixnum dmns))
	   (when (> dmns n)
	     (return-from rslt +empty-list+))
	   (setf dmns (1+ dmns))
	   (do ((rslt +empty-list+)
		(count (binomial-n-p (1+ n) dmns))
		(gmsm (mask (1+ n)) (1- gmsm)))
	       ((zerop count) rslt)
	     (when (= (logcount gmsm) dmns)
	       (push gmsm rslt)
	       (decf count)))))
    (the basis #'rslt)))


(DEFUN SOFT-DELTA-N-BASIS (n)
  (declare (fixnum n))
  (flet ((rslt (dmns)
	   (when (> dmns n)
	     (return-from rslt +empty-list+))
	   (setf dmns (1+ dmns))
	   (do ((rslt +empty-list+)
		(count (binomial-n-p (1+ n) dmns))
		(gmsm (mask (1+ n)) (1- gmsm)))
	       ((zerop count) rslt)
	     (when (= (logcount gmsm) dmns)
	       (push (d gmsm) rslt)
	       (decf count)))))
    (the basis #'rslt)))


(DEFUN DELTA (dmns)
  (declare (fixnum dmns))
  (the simplicial-set
       (build-smst
	:cmpr #'f-cmpr
	:basis (delta-n-basis dmns)
	:bspn 1
	:face #'delta-face
	:intr-dgnl #'delta-dgnl
	:dgnl-strt :gnrt
	:intr-bndr #'delta-bndr
	:bndr-strt :gnrt
	:orgn `(delta ,dmns))))


(DEFUN SOFT-DELTA (dmns)
  (declare (fixnum dmns))
  (the simplicial-set
       (build-smst
	:cmpr #'soft-delta-cmpr
	:basis (soft-delta-n-basis dmns)
	:bspn (d 1)
	:face #'soft-delta-face
	:intr-dgnl #'soft-delta-dgnl :dgnl-strt :gnrt
	:intr-bndr #'soft-delta-bndr :bndr-strt :gnrt
	:orgn `(soft-delta ,dmns))))


(DEFUN DELTAB-CMPR (gmsm1 gmsm2)
  (declare (fixnum gmsm1 gmsm2))
  (if (= 1 (logcount gmsm1))
      :equal
      (f-cmpr gmsm1 gmsm2)))


(DEFUN DELTAB-BNDR (dmns gmsm)
  (declare (fixnum dmns gmsm))
  (the cmbn
       (if (< dmns 2)
	   (zero-cmbn (1- dmns))
	   (make-cmbn
            :degr (1- dmns)
            :list (do ((rslt +empty-list+)
		       (gmsm2 gmsm (ash gmsm2 -1))
		       (pmark 1 (ash pmark +1))
		       (sign 1))
		      ((zerop gmsm2) rslt)
                    (declare
		     (list rslt)
		     (fixnum gmsm2 pmark sign))
                    (when (oddp gmsm2)
		      (push (term sign (logxor gmsm pmark)) rslt)
		      (setf sign (- sign))))))))


(DEFUN DELTAB2-FACE (indx dmns gmsm)
  (declare
   (fixnum indx dmns gmsm))
  (the absm
       (progn
	 (when (= 2 dmns)
	   (return-from deltab2-face (absm 1 1)))
	 (do ((pmark 1 (ash pmark 1))
	      (bmark indx)
	      (gmsm2 gmsm (ash gmsm2 -1)))
	     (nil)
	   (declare (fixnum pmark bmark gmsm2))
	   (when (oddp gmsm2)
	     (when (minusp (decf bmark))
	       (return-from deltab2-face (absm 0 (logxor gmsm pmark)))))))))


(DEFUN DELTAB2-DGNL (dmns gmsm)
  (declare (fixnum dmns gmsm))
  (the cmbn
       (make-cmbn
	:degr dmns
	:list (if (zerop dmns)
		  (list (term 1 (tnpr 0 gmsm 0 gmsm)))
		  (do ((rslt +empty-list+)
		       (ldegr dmns)
		       (indx (1- (integer-length gmsm)) (1- indx)))
		      ((minusp indx))
		    (declare (list rslt) (fixnum indx))
		    (when (logbitp indx gmsm)
		      (push (term 1 (tnpr
				     ldegr (logand gmsm (mask (1+ indx)))
				     (- dmns ldegr)
				     (logandc2 gmsm (mask indx))))
			    rslt)
		      (when (minusp (decf ldegr))
			(setf rslt (delete 1 rslt :key #'caaddr))
			(setf (gnrt1 (gnrt (first rslt)))
			      (setf (gnrt2 (gnrt (car (last rslt))))
				    1))
			(return (delete 1 rslt :key #'cadddr)))))))))


(DEFUN DELTAB2-BNDR (dmns gmsm)
  (declare (fixnum dmns gmsm))
  (the cmbn
       (if (< dmns 3)
	   (zero-cmbn (1- dmns))
	   (make-cmbn
            :degr (1- dmns)
            :list (do ((rslt +empty-list+)
		       (gmsm2 gmsm (ash gmsm2 -1))
		       (pmark 1 (ash pmark +1))
		       (sign 1))
		      ((zerop gmsm2) rslt)
                    (declare
		     (list rslt)
		     (fixnum gmsm2 pmark sign))
                    (when (oddp gmsm2)
		      (push (term sign (logxor gmsm pmark)) rslt)
		      (setf sign (- sign))))))))


(DEFUN DELTAB ()
  (the simplicial-set
       (build-smst
	:cmpr #'deltab-cmpr
	:basis :locally-effective
	:bspn 1
	:face #'delta-face
	:intr-dgnl #'delta-dgnl
	:dgnl-strt :gnrt
	:orgn '(deltab))))


(DEFUN DELTAB2 ()
  (the simplicial-set
       (build-smst
	:cmpr #'f-cmpr
	:basis :locally-effective
	:bspn 1
	:face #'deltab2-face
	:intr-dgnl #'deltab2-dgnl
	:dgnl-strt :gnrt
	:orgn '(deltab2))))