The Magma Help System

Magma provides extensive online help facilities that can be accessed in different ways.

The easiest way to get some information about any Magma intrinsic is by typing: (Here we assume you to be interested in FundamentalUnit)

> FundamentalUnit;

> FundamentalUnit;
Intrinsic 'FundamentalUnit'

Signatures:

    (<FldQuad> K) -> FldQuadElt
    (<RngQuad> O) -> RngQuadElt

        The fundamental unit of K or O

    (<RngQuad> R) -> RngQuadElt

        Fundamental unit of the real quadratic order.

> ?FundamentalUnit

But now several things could happen depending on the installation. Using the default, you get

===========================================================
PATH: /magma/ring-field-algebra/quadratic/operation/\
      class-group/FundamentalUnit
KIND: Intrinsic
===========================================================
FundamentalUnit(K) : FldQuad -> FldQuadElt
FundamentalUnit(O) : RngQuad -> RngQuadElt

    A generator for the unit group of the order O or the 
maximal order
    of the quadratic field K.
===========================================================

Second, a WWW-browser could start on the part of the online help describing your function (or at least the index of the first character). Third, some arbitrary program could be called to provide you with the information.

If SetVerbose("Help", true); is set, Magma will show the exact command used and the return value obtained.

SetHelpExternalBrowser(S, T) : MonStgElt, MonStgElt ->

SetHelpExternalBrowser(S) : MonStgElt ->

Defines the external browser to be used if SetHelpUseExternalBrowser(true) is in effect. The string has to be a valid command taking exactly one argument (%s) which will we replaced by a URL. In case two strings are provided, the second defines a fall-back system. Typical use for this is to first try to use an already running browser and if this fails, start a new one.

SetHelpUseExternalBrowser(b) : BoolElt ->

Tells Magma to actually use (or stop to use) the external browser. If both SetHelpUseExternalSystem and SetHelpUseExternalBrowser are set to true, the assignment made last will be effective.

SetHelpExternalSystem(s) : MonStgElt ->

This will tell Magma to use a user defined external program to access the help. The string has to contain exactly one %s which will be replaced by the argument to ?. The resulting string must be a valid command.

SetHelpUseExternalSystem(b) : BoolElt ->

Tells Magma to actually use (or stop to use) the external help system. If both SetHelpUseExternalSystem and SetHelpUseExternalBrowser are set to true, the assignment made last will be effective.

GetHelpExternalBrowser() : -> MonStgElt, MonStgElt

Returns the currently used command strings.

GetHelpExternalSystem() : -> MonStgElt

Returns the currently used command string.

GetHelpUseExternal() : -> BoolElt, BoolElt

The first value is the currently used value from SetHelpUseExternalBrowser, the second reflects SetHelpUseExternalSystem.

Internal Help Browser

Magma has a very powerful internal help-browser that can be entered with

> ??