diff options
Diffstat (limited to 'src/algebra/indexedp.spad.pamphlet')
| -rw-r--r-- | src/algebra/indexedp.spad.pamphlet | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/src/algebra/indexedp.spad.pamphlet b/src/algebra/indexedp.spad.pamphlet index bbb78cd0..c296f271 100644 --- a/src/algebra/indexedp.spad.pamphlet +++ b/src/algebra/indexedp.spad.pamphlet @@ -93,7 +93,12 @@ IndexedProductTerm(A,S): Public == Private where IndexedDirectProductObject(A,S): Public == Private where A: BasicType S: OrderedType - Public == IndexedDirectProductCategory(A,S) + Public == IndexedDirectProductCategory(A,S) with + combineWithIf: (%,%, (A,A) -> A, (A,A) -> Boolean) -> % + ++ \spad{combineWithIf(u,v,f,p)} returns the result of combining + ++ index-wise, coefficients of \spad{u} and \spad{u} if when + ++ satisfy the predicate \spad{p}. Those pairs of coefficients + ++ which fail\spad{p} are implicitly ignored. Private == List IndexedProductTerm(A,S) add if A has CoercibleTo OutputForm and S has CoercibleTo OutputForm then coerce(x:%):OutputForm == @@ -113,6 +118,38 @@ IndexedDirectProductObject(A,S): Public == Private where index first rep x terms x == rep x convert l == per l + combineWithIf(u, v, f, p) == + x := rep u + y := rep v + empty? x => v + empty? y => u + z: Rep := nil + prev: Rep := nil + while not empty? x and not empty? y repeat + xt := first x + yt := first y + index xt > index yt => + t := [xt] + if empty? z then z := t + else setrest!(prev,t) + prev := t + x := rest x + index xt < index yt => + t := [yt] + if empty? z then z := t + else setrest!(prev,t) + prev := t + y := rest y + not p(coefficient xt, coefficient yt) => iterate + t := [term(index xt, f(coefficient xt, coefficient yt))] + if empty? z then z := t + else setrest!(prev,t) + prev := t + x := rest x + y := rest y + if empty? x then setrest!(prev,y) + else if empty? y then setrest!(prev,x) + per z @ \section{domain IDPAM IndexedDirectProductAbelianMonoid} |