fn λ → ÷ ≟ ← ⊗

→ and ← can now be used for assignment, not just <- and ->.

function(x) x**3 can now be written fn(x) x**3, λ(x) x**3, or ƒ(x) x**3.

÷ means division.

⊗ means the Kronecker/tensor product. It matches R's existing %x% operator; %o% remains R's outer product.

Existing R spelling remains available: <-, <<-, ->, ->>, ==, function, and %x% still work.

answer ← 8 ÷ 2
answer ≟ 4

The last line returns

[1] TRUE

because ≟ tests equality.

A matrix tensor product can be written directly:

A ← matrix(c(1, 2,
             3, 4), nrow = 2, byrow = TRUE)
B ← matrix(c(0, 5,
             6, 7), nrow = 2, byrow = TRUE)
A ⊗ B

which produces the same 4 × 4 matrix as A %x% B and kronecker(A, B).

this	does
x ← 3	assign
x ↞ 3	assign in an enclosing frame
3 → x	assign
3 ↠ x	assign in an enclosing frame
left ≟ right	test equality
fn(x) expression, λ(x) expression, or ƒ(x) expression	construct a function
left ÷ right	divide
left ⊗ right	Kronecker/tensor product

Prefer ≟ for equality. ?=, =?, ?=?, ¿=?, =, and == are aliases for the same test.

Parameters are still supplied with =.

clean.mean ← λ(x) mean(x, na.rm = TRUE)

---

Actually this is worse than I thought it would be, I thought there would be no downsides....

Only the = equality alias is contextual. Inside another call, wrap an equality comparison written with = in parentheses so it cannot be read as an argument name:

stopifnot((answer = 4))

Code that used a single = as assignment must use an arrow in this R. The comma and argument-label rules have otherwise been left alone.

fn also used to be an ordinary name. It is reserved here, so old code using bare fn as a variable or argument must choose another name. This source uses fun; in particular, write optim(par, fun = ...) rather than optim(par, fn = ...).

---

You do not have to give up ordinary R

The tested Linux instructions install this build in its own folder and use a separate package library. They do not remove ordinary R, alter your projects, rewrite your scripts, or upload your work. Close this R and launch ordinary R as before whenever you want to switch back.