Jonathan Frech

Jonathan Frech


I am blogging on, mainly about programming, poetry and occasionally photography.


Zpr'(h is a symbolic, directionally super-lazy esoteric programming language I wrote in the tenth week of 2020.

Examplary prime number generation

001<| prelude.zpr
003(prime? .p) |> (not (any \
004    (section @ | p) (range 2 p)))
005primes |> (filter prime? \
006    (drop 2 |N0))
007main |> (take 10 primes)

For further detail, I refer to my blog post Zpr'(h.
Zpr'(h's source code is currently hosted on GitHub.


krrp is a functional turing complete esolang focussing on cryptic conciseness whilst preserving capability.
It currently has one interpreter, written in pure C.

Examplary prime number generation

002 ,^d: ?<dn
003  ?%nd @+d1
004  0 1. 2.
006\L [filter]
007 ;[prime?]
008 [range]2$99.

The above krrp program calculates all primes below a hundred. Try it online!

For further detail, I refer to my blog post krrp.
krrp's source code is currently hosted on GitHub.


I am a fond user of the version control system git and publish larger projects of mine at GitHub. Politically I have to admit being torn to use the aforementioned Microsoft product. However, I currently value its size-induced expected reliability.
All my repositories are licensed under the MIT license, thus feel free to use my source code to your hearts content.


The On-Line Encyclopedia of Integer Sequences – OEIS – collects and curates integer sequences.

My most recent contribution to the OEIS is sequence A325902:

Numbers whose neighbor's prime factors with multiplicity can be partitioned into two multisets of equal sum.

My OEIS Userpage.


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Further licensing information specific to my blog can be found at

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Jonathan Frech
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