%DEF fill Fill←•internal.HasFill◶'e'‿{⊑1↑0⥊𝕩}

%USE fill ⋄ F←⌊  ⋄ ⟨0,1,{⇐},+,@,'𝕩'⟩ Fill∘F⌜ ⟨⟨⟩, ↕0‿0, ↕0, 0‿2⥊↕0, "", 2‿0⥊""⟩ %NHEAPVERIFY  %%  2‿4/[⟨'e',0‿0,0,0,'e','e'⟩,⟨'e','e','e','e','e','e'⟩]
%USE fill ⋄ F←+  ⋄ ⟨0,1,{⇐},+,@,'𝕩'⟩ Fill∘F⌜ ⟨⟨⟩, ↕0‿0, ↕0, 0‿2⥊↕0, "", 2‿0⥊""⟩ %NHEAPVERIFY  %%  6‿6⥊⟨'e',0‿0,0,0,' ',' ','e',0‿0,0,0,' ',' ','e','e','e','e','e','e','e','e','e','e','e','e','e',"  ",' ',' ','e','e','e',"  ",' ',' ','e','e'⟩
%USE fill ⋄ F←-  ⋄ ⟨0,1,{⇐},+,@,'𝕩'⟩ Fill∘F⌜ ⟨⟨⟩, ↕0‿0, ↕0, 0‿2⥊↕0, "", 2‿0⥊""⟩ %NHEAPVERIFY  %%  6‿6⥊⟨'e',0‿0,0,0,'e','e','e',0‿0,0,0,'e','e','e','e','e','e','e','e','e','e','e','e','e','e','e',"  ",' ',' ',0,0,'e',"  ",' ',' ',0,0⟩
%USE fill ⋄ F←-˜ ⋄ ⟨0,1,{⇐},+,@,'𝕩'⟩ Fill∘F⌜ ⟨⟨⟩, ↕0‿0, ↕0, 0‿2⥊↕0, "", 2‿0⥊""⟩ %NHEAPVERIFY  %%  6‿6⥊⟨'e',0‿0,0,0,' ',' ','e',0‿0,0,0,' ',' ','e','e','e','e','e','e','e','e','e','e','e','e','e','e','e','e',0,0,'e','e','e','e',0,0⟩
%USE fill ⋄ (> !∘≡○Fill ⊢)¨ ⟨↕0, ""⟩
%USE fill ⋄ ⟨⊢,Fill,Fill Fill⟩{𝕎𝕩}¨< 0⥊0‿1⊔2⥊<↕2 %% ⟨⟨⟩,⟨⟩,0‿0⟩

!¬•internal.HasFill <"hello"‿+
%USE fill ⋄ fa ← Fill¨ a←⟨0, 2‿3‿4, 2‿0‿4, 0‿2‿3, 2⟩⥊⟜<⌜⟨0,'a',{⇐},1‿2⟩ ⋄ {𝕊f : fa {!𝕨≡Fill F 𝕩}¨ a}¨ ⟨⥊, 0⊸/, 0⊸⥊, 0⊸↑, 0⊸↓, ⊑∘⋈⟩ ⋄ fa %% 5/≍⟨0,' ','e',0‿0⟩

%USE fill ⋄     a←10⥊<1‿2 ⋄ {        a∾↩𝕩⋄@}¨100⥊<<1‿2 ⋄ Fill a %% 0‿0
%USE fill ⋄     a←10⥊<1‿2 ⋄ {a↩0↑a ⋄ a∾↩𝕩⋄@}¨100⥊<<1‿2 ⋄ Fill a %% 0‿0
%USE fill ⋄ {𝕊: a←10⥊<1‿2 ⋄ {        a∾↩𝕩⋄@}¨(𝕩⥊<<1‿2)∾<<1‿2‿3 ⋄ a!'e'≡Fill a}¨ ↕100
%USE fill ⋄ {𝕊: a←10⥊<1‿2 ⋄ {a↩0↑a ⋄ a∾↩𝕩⋄@}¨(𝕩⥊<<1‿2)∾<<1‿2‿3 ⋄ a!'e'≡Fill a}¨ ↕100

# TODO:
# ⟨↑‿3⥊↕10 ⋄ ↑‿3⥊<¨↕10 ⋄ ↑‿3⥊<˘↕10⟩
# 5‿¯5↑⌜⟨↕2 ⋄ "ab" ⋄ <¨↕2 ⋄ <˘↕2⟩