// tcK - 1 stack

/ verbs

k:,/+{.:'(x,":";x)}'"~!@#$%^&*_-+=|:<,>.?"				/ F1,F2 = (~:;!:;..;~;!;..)
v:-&0 20 20								/ valences
n:{[n;f]{f[(-n)_ x].(-n)#x}}						/ n-ary application

/ stack operators

dup:n[1]{x,(y;y)}							/      X -> X X
cons:n[2]{x,,(,y),z}							/ X [..] -> [X ..]
swap:n[2]{x,(z;y)}							/    X Y -> Y X

/ combinators

i:n[1]{E[x;y]}								/ [..] -> ..
dip:n[2]{E[x;z,,y]}							/ X Y [P] -> X P Y
linrec:n[4]{[x;i;t;e;f]:[E_[x;i];E[x;t];E[_f[E[x;e];i;t;e;f];f]]}	/ t if i else: e, recurse, f
cond:n[1]{i:0;do[-1+#y;if[E_[x;y[i;0]];:E[x;y[i;1]]];i+:1];E[x;y i]}	/ [.. [X Y] .. Z] -> Y if X else Z

/ adverbs (k combinators)

right:n[3]{[x;a;b;p]x,,a{*e(y;z),x}[p]/:b}				/ X Y f2 -> X f2/:Y
over:n[2]{x,,{*e(y;z),x}[z]/y}						/   X f2 ->   f2/X
converge:n[2]{x,,{*e(,y),x}[z]/y}					/   X f1 ->   f1/X

/ apply

a:{:[~#y;(x;y);(4:*y)_in 4 7;(f[x;*y];1_ y);(x,1#y;1_ y)]}		/ apply if program-stack not empty
f:{:[(#k)>i:k?y;(v[i]_ x),,y . v[i]#x;y x]}				/ apply k or tck0 program

/ eval

E:{*(a .)/(x;y)}							/ evaluate y on x
E_:{*-1#E[x;y]}								/ last of evaluate y on x
e:E[()]									/ evaluate y on ()

/ trace

T:{(a .)\(x;y)}								/ trace evaluation of y on x
t:T[()]									/ trace evaluation of y on ()

/ define program P:d[(..)] (metalinguistic)

d:{E[y;x]}								/ evaluate x on y