(Btw, just a workaround in case someone does encounter this, you can directly call the factory metohd with an empty context to overwrite the functions on the instance, but I am not sure what side effects that might have.)

Hm yeah that is confusing, sorry. Let me try to explain what's going on.

The npm library contains a static function create(factories, config), and a collection of factory functions all and individual factories. When you create a mathjs instance like math = create(factories, config), it will contain a function math.create(config) which is bound to the factories of the original instance. So, it is not the same as the static version and can only create a new instance with the same factories and a changed configuration. Probably a better name for this function would be math.cloneInstance(config) or something like that.

Now, the browser bundle is not the same as the npm library: it exports a mathjs instance. So, the not the static function create(factories, config) and factory functions all, but the bound function math.create(config). The browser bundle doesn't have the collection all like the npm import does (if you print all in your jsfiddle, you will see it is undefined).

So in short: it's not possible to do with the browser bundle right now. It would be good to think through if we can address this issue.

I did a quick test: if we change the contents of defaultInstance.js to the following:

import * as math from './index.js'

export default math

And then create the browser bundle, your jsfiddle example works as expected. The browser bundle grows from 183 KB to 202 KB when zipped: it is larger because it now exports all named factories.

I "forked" a version with the suggested fix that did the trick for me, so thank you very much for that 👍 .

That's good news, glad to here this workaround works.

I still have to think through how to solve this issue. At least we should rename math.create into something like math.cloneInstance to prevent confusion. And it would be good to add all the exports to prevent any confusion, only, it's quite some additional kb's. So either we make the default bundle bigger, or we can publish an addition bundle including the factory function exports.