#!/usr/local/bin/apl --script

⍝ Run with:  ./TGI0.apl

⍝ The square root of ¯1, a pure imaginary number.
⍙J ← 0J1

⍝ CMPLX is an array function.
∇z ← m CMPLX n
  z ← m + ⍙J × n
∇


⍝ NORMJ is an array function.
∇ z ← NORMJ m
  z ← m × + m
∇


∇ z ← a MODTST b; r0; r1; r2
  z ← 0
 → ( ( a = 0 ) ∨ z ← ( ( r1 ← NORMJ a ∣ b ) < r0 ← NORMJ a ) ) / 0
  ⍞ ← "a = "
  ⍞ ← a
  ⍞ ← ", b = "
  ⍞ ← b
  ⍞ ← ", ( NORMJ a ∣ b = "
  ⍞ ← r1
  ⍞ ← " ) ≥ ( NORMJ a = "
  ⍞ ← r0
  ⍞ ← " )"
  ⎕ ← " "
  ⍞ ← "r2 = b ÷ a = "
  ⍞ ← r2 ← b ÷ a
  ⍞ ← ", b = r2 × a ="
  ⍞ ← r2 × a
  ⎕ ← " "
∇

cnt ← 21
bgn ← ¯1 - cnt2 ← ⌊ cnt ÷ 2
a ← b ← ints ← bgn + ⍳ cnt
alpha ← ⊖ ⍉ a ∘.CMPLX b

⎕ ← " "
foo ← alpha ∘.MODTST alpha

⍝ rhp ← ⍉ ( ⍳ cnt2 ) ∘.CMPLX ( bgn + ⍳ cnt )
⍝ foo ← rhp ∘.MODTST rhp