addOne:= Op("+").fp(1); addOne(5) //-->6
minusOne:=Op("-").fp1(1); minusOne(5) //-->4, note that this fixed 1 as the second parameter
   // fix first and third parameters:
foo:=String.fpM("101","<foo>","</foo>"); foo("zkl"); //-->"<foo>zkl</foo>"
fcn g(x){x+1} f:=fcn(f,x){f(x)+x}.fp(g); f(5); //-->11
f:=fcn(f,x){f(x)+x}.fp(fcn(x){x+1}); // above with lambdas all the way down